Anatomy of the stomach in children. Anatomical and physiological features of the digestive system in children. Characteristics of intestinal microflora in children

05.03.2020

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FGAOU VPO North-Eastern Federal University named after M. K. Ammosova "

Medical Institute

by discipline: "Hygiene"

On the topic: "Anatomical and physiological features of the digestive system in children and adolescents"

Completed by: Gotovtseva

Ulyana Afanasyevna

Group: LD 306-1

Checked by: Fedoseeva

Lyudmila Romanovna

Yakutsk 2014

Introduction

Food contains substances that, without preliminary processing, cannot penetrate from the digestive system into the blood. Food undergoes physical changes (grinding, grinding, moisturizing, dissolving) and chemical (digestion). The path that food takes is called the digestive tract. Its length in humans is 6-8 m. The wall of the tract, consisting mainly of smooth muscle tissue, is covered with a mucous membrane from the inside. Its cells produce mucus. Food processing begins in the mouth: here it is moistened with saliva and crushed by the teeth.

Food that gets into the mouth, and then into the subsequent sections of the digestive system, undergoes complex physicochemical transformations. And as a result of physical and chemical processing, nutrients are broken down into simpler ones and absorbed into the blood. Therefore, the importance of digestion is to replenish the body with the necessary building (plastic) substances and energy. digestion physiological intestinal esophagus

As a child grows and develops, the need for nutrients increases. At the same time, the body of young children can not assimilate all kinds of food. In terms of quantity and quality, the child's food must meet the characteristics of the digestive tract, satisfy his need for plastic substances and energy (contain in sufficient quantities the proteins, fats, carbohydrates, minerals, water and vitamins the child needs).

The digestive system of children is not only functional, but also differs from the digestive organs of an adult in its linear dimensions and volume of cavities.

1. The period of intrauterine formation of the digestive system

The laying of the digestive organs occurs at a very early stage of embryonic development: from the 7th day to the 3rd month of intrauterine life of the fetus. By the 7-8th day, the organization of the primary intestine begins from the endoderm, and on the 12th day, the primary intestine is divided into 2 parts: intraembryonic (future digestive tract) and extraembryonic (yolk sac). Initially, the primary intestine has oropharyngeal and cloacal membranes. At the 3rd week of intrauterine development, the oropharyngeal membrane melts, at the 3rd month - the cloacal membrane. In the process of development, the intestinal tube passes the stage of a dense "cord", when the proliferating epithelium completely closes the intestinal lumen. Then the process of vacuolization takes place, ending with the restoration of the lumen of the intestinal tube. With partial or complete violation of vacuolization, the intestinal lumen remains (almost or completely) closed, which leads either to stenosis or to atresia and obstruction. By the end of 1 month. intrauterine development, 3 parts of the primary intestine are outlined: anterior, middle and posterior; there is a closure of the primary intestine in the form of a tube. From the 1st week, the formation of various parts of the digestive tract begins: the pharynx, esophagus, stomach and part of the duodenum with the rudiments of the pancreas and liver develop from the anterior intestine; part of the duodenum, jejunum and ileum form from the midgut; all parts of the large intestine develop from the hindgut.

In the antenatal period, the anterior gut develops most intensively and gives many bends. In the third month of intrauterine development, the process of movement of the small intestine (from right to left, behind the superior mesenteric artery) and the large intestine (from left to right of the same artery) occurs, which is called bowel rotation.

There are three periods of bowel rotation:

1) turn by 90 °, the large intestine is on the left, the small intestine is on the right; 2) a 270є rotation, the large and small intestines have a common mesentery; 3) fixation of the intestine ends, the small intestine acquires a separate mesentery.

If the process of intrauterine bowel rotation stops at the first stage, then midgut volvulus may occur. The time of bloat is different: from prenatal period to old age. If the second period of rotation is disturbed, the following may occur: failed bowel rotation, duodenal obstruction and other anomalies. In case of violation of the third stage of rotation, the fixation of the intestine changes, which leads to the formation of defects in the mesentery, as well as various pockets and bags, predisposing to infringement of intestinal loops and to internal hernias.

At the same time, vessels are formed that go to the yolk sac and the intestinal tract. Arteries extend from the aorta. The veins are directed directly to the venous sinus.

At the 10th week, the laying of the gastric glands begins, however, their differentiation, both morphologically and functionally, by the time of the birth of the child is not complete.

Between the 10th and 22nd weeks of intrauterine development, the formation of intestinal villi occurs - most of the enzymes of membrane digestion appear, but the activation of some of them, for example lactase, occurs only by 38-40 weeks of gestation.

From the 16-20th week, the system begins to function as a digestive organ: the swallowing reflex is already expressed, gastric juice contains pepsinogen, intestinal juice - trypsinogen.

The fetus swallows and digests a large amount of amniotic fluid, which is similar in composition to the extracellular fluid and serves as an additional source of nutrition for the fetus (amniotic nutrition).

2. Anatomical and physiological features of the digestive system

The morphological and physiological characteristics of the digestive organs in children are especially pronounced in infancy. In this age period, the digestive apparatus is adapted mainly for the assimilation of breast milk, the digestion of which requires the least amount of enzymes (lactotrophic nutrition). A baby is born with a well-pronounced sucking and swallowing reflex. The act of sucking is provided by the anatomical features of the oral cavity of a newborn and an infant. When sucking, the baby's lips tightly grip the mother's nipple with the areola. The jaws squeeze it, and the communication between the oral cavity and the outside air stops. A cavity with negative pressure is created in the child's mouth, which is facilitated by the lowering of the lower jaw (physiological retrognathia) along with the tongue down and back. Breast milk enters the rarefied space of the mouth.

Oral cavity. The main function of the baby's oral cavity after birth is to provide the sucking act. These features are: small size of the oral cavity, large tongue, well-developed musculature of the lips and chewing muscles, transverse folds on the mucous membrane of the lips, roller-like thickening of the gums, there are lumps of fat (Bisha's lumps) in the cheeks, which give elasticity to the cheeks.

The mucous membrane of the oral cavity is tender, richly supplied with blood vessels and relatively dry. Dryness is caused by insufficient development of the salivary glands and saliva deficiency in children up to 3-4 months of age. The mucous membrane of the oral cavity is easily vulnerable, which should be taken into account when carrying out the toilet in the oral cavity. The development of the salivary glands ends by 3-4 months, and from this time, increased salivation begins (physiological salivation). Saliva is the result of the secretion of three pairs of salivary glands (parotid, submandibular and sublingual) and small glands of the oral cavity. The reaction of saliva in newborns is neutral or slightly acidic. From the first days of life, it contains an amylolytic enzyme. It contributes to the mucousiness of food and foaming; from the second half of life, its bactericidal activity increases.

The entrance to the larynx in an infant lies high above the lower edge of the palatine curtain and is connected to the oral cavity; thus, food moves to the sides of the protruding larynx through the communication between the oral cavity and the pharynx. Therefore, the baby can breathe and suck at the same time. From the mouth, food passes through the esophagus into the stomach.

Esophagus. At the beginning of development, the esophagus looks like a tube, the lumen of which is filled due to the proliferation of the cell mass. At 3-4 months of intrauterine development, the laying of glands is observed, which begin to actively secrete. This promotes the formation of a lumen in the esophagus. Violation of the recanalization process is the cause of congenital narrowings and strictures of the esophagus.

In newborns, the esophagus is a fusiform muscle tube lined with a mucous membrane from the inside. The entrance to the esophagus is located at the level of the disc between the III and IV cervical vertebrae, by the age of 2 years - at the level of the IV-V cervical vertebrae, at the age of 12 - at the level of the VI-VII vertebrae. The length of the esophagus in a newborn is 10-12 cm, at the age of 5 years - 16 cm; its width in a newborn is 7-8 mm, by 1 year - 1 cm and by 12 years - 1.5 cm (the size of the esophagus must be taken into account when carrying out instrumental studies).

Anatomical narrowing of the esophagus in newborns and children of the first year of life is relatively weak. The peculiarities of the esophagus include the complete absence of glands and insufficient development of muscular-elastic tissue. Outside the act of swallowing, the passage of the pharynx into the esophagus is closed. The transition of the esophagus to the stomach in all periods of childhood is located at the level of the X-XI thoracic vertebrae.

Stomach. Located in the left hypochondrium, its cardial part is fixed to the left of the X thoracic vertebra, the pylorus is located near the midline at the level of the XII thoracic vertebra, approximately in the middle between the umbilicus and the xiphoid process. In infants, the stomach is horizontal, but as soon as the baby begins to walk, it takes a more upright position.

By the time the baby is born, the fundus and the cardiac part of the stomach are not sufficiently developed, and the pyloric part is much better than the frequent regurgitation is explained. Regurgitation is also facilitated by swallowing air when sucking (aerophagia), with improper feeding technique, short frenulum of the tongue, greedy sucking, too rapid release of milk from the mother's breast.

The capacity of the stomach of a newborn is 30-35 ml, by 1 year it increases to 250-300 ml, by 8 years it reaches 1000 ml.

The mucous membrane of the stomach is delicate, rich in blood vessels, poor in elastic tissue, and contains few digestive glands. The muscle layer is underdeveloped. There is a meager secretion of gastric juice with low acidity.

The digestive glands begin to function in utero (lining and main), but in general, the secretory apparatus of the stomach in children of the first year of life is insufficiently developed and its functional abilities are low.

The gastric juice of an infant contains the same components as the gastric juice of an adult: rennet, hydrochloric acid, pepsin, lipase, but their content is reduced, especially in newborns, and increases gradually.

The total acidity in the first year of life is 2.5-3 times lower than that of adults, and is equal to 20-40. Free hydrochloric acid is determined during breastfeeding after 1-1.5 hours, and with artificial feeding - 2.5-3 hours after feeding. The acidity of gastric juice is subject to significant fluctuations depending on the nature and diet, the state of the gastrointestinal tract.

An important role in the implementation of the motor function of the stomach belongs to the activity of the pylorus, thanks to the reflex periodic opening and closing of which the food masses pass in small portions from the stomach into the duodenum. The first months of life, the motor function of the stomach is poorly expressed, the peristalsis is sluggish, the gas bubble is enlarged. In infants, it is possible to increase the tone of the stomach muscles in the pyloric section, the maximum manifestation of which is pylorospasm. In older age, sometimes there is a cardiospasm.

Functional insufficiency decreases with age, which is explained, first, by the gradual development of conditioned reflexes to food stimuli; secondly, the complication of the child's nutritional regimen; third, the development of the cerebral cortex. By the age of 2, the structural and physiological features of the stomach correspond to those of an adult.

The duodenum of a newborn is located at the level of the 1st lumbar vertebra and has a rounded shape. By the age of 12, it descends to the III-IV lumbar vertebra. The length of the duodenum up to 4 years is 7-13 cm (in adults up to 24-30 cm). In young children, it is very mobile, but by the age of 7, adipose tissue appears around it, which fixes the intestine and reduces its mobility.

The jejunum occupies 2/5, and the ileum 3/5 of the length of the small intestine without the duodenum. There is no clear border between them.

The ileum ends with an ileocecal valve. In young children, its relative weakness is noted, and therefore the contents of the cecum, the richest in bacterial flora, can be thrown into the ileum. In older children, this condition is considered pathological.

The small intestine in children occupies an unstable position, which depends on the degree of its filling, body position, the tone of the intestines and muscles of the peritoneum. Compared to adults, it has a relatively long length, and the intestinal loops lie more compactly due to the relatively large liver and underdevelopment of the small pelvis. After the first year of life, as the small pelvis develops, the location of the loops of the small intestine becomes more constant.

The small intestine of an infant contains relatively many gases, which gradually decrease in volume and disappear by the age of 7 (adults normally have no gas in the small intestine).

Other features of the intestines in infants and young children include:

· High permeability of the intestinal epithelium;

· Poor development of the muscle layer and elastic fibers of the intestinal wall;

· Tenderness of the mucous membrane and a high content of blood vessels in it;

· Good development of villi and folds of the mucous membrane in case of insufficiency of the secretory apparatus and incomplete development of nerve pathways.

This contributes to the easy occurrence of functional disorders and favors the penetration into the blood of non-split food constituents, toxic-allergic substances and microorganisms.

After 5-7 years, the histological structure of the mucous membrane no longer differs from its structure in adults.

The mesentery, which is very thin in newborns, increases significantly in length during the first year of life and descends with the intestine. This, apparently, causes the child to have relatively frequent volvulus and intussusception.

The lymph flowing from the small intestine does not pass through the liver, so the products of absorption, together with the lymph through the thoracic duct, enter directly into the circulating blood.

The large intestine is as long as a child's height. Parts of the colon are developed to varying degrees. The newborn has no omental processes, the ribbons of the colon are barely outlined, the haustra are absent until the age of six months. The anatomical structure of the colon after 3-4 years of age is the same as in an adult.

The funnel-shaped cecum is located higher, the younger the child. In a newborn, it is located directly under the liver. The higher the cecum is located, the more the ascending is underdeveloped. The final formation of the cecum ends by one year.

The appendix in a newborn has a conical shape, a wide open entrance and a length of 4-5 cm, by the end of 1 year - 7 cm (in adults 9-12 cm). It has greater mobility due to the long mesentery and can be found in any part of the abdominal cavity, but most often it occupies a retrocecal position.

The rim of the colon surrounds the loops of the small intestine. The ascending part of the colon in a newborn is very short (2-9 cm), begins to increase after a year.

The transverse part of the colon in a newborn is located in the epigastric region, has a horseshoe shape, length from 4 to 27 cm; by the age of 2, it approaches a horizontal position. The mesentery of the transverse part of the colon is small and relatively long, due to which the intestine can easily move when filling the stomach and small intestine.

The descending part of the colon in newborns is narrower than the rest of the colon; its length doubles by 1 year, and by 5 years it reaches 15 cm. It is weakly mobile and rarely has a mesentery.

The sigmoid colon is the most mobile and relatively long part of the large intestine (12-29 cm). Up to 5 years old, it is usually located in the abdominal cavity due to an underdeveloped small pelvis, and then descends into the small pelvis. Its mobility is due to the long mesentery. By the age of 7, the intestine loses its mobility as a result of shortening of the mesentery and the accumulation of adipose tissue around it.

The rectum in children of the first months is relatively long and, when filled, can occupy a small pelvis. In a newborn, the rectal ampulla is poorly differentiated, adipose tissue is not developed, as a result of which the ampoule is poorly fixed. The rectum takes its final position by 2 years. Due to the well-developed submucosal layer and poor fixation of the mucous membrane in young children, its loss is often observed.

The anus in children is located more dorsally than in adults, at a distance of 20 mm from the coccyx.

The intestinal secretory apparatus as a whole is formed. Even in the smallest, in the intestinal juice secreted by enterocytes, the same enzymes are determined as in adults (enterokinase, alkaline phosphatase, erepsin, lipase, amylase, maltase, nuclease), but their activity is low.

The infant has a special cavity intracellular digestion, adapted to lactotropic nutrition, and intracellular, carried out by pinocetosis. The breakdown of food is mainly influenced by the secretion of the pancreas, which contains trypsin (acting proteolytically), amylase (breaks down polysaccharides and converts them into monosaccharides) and lipase (breaks down fats). Due to the low activity of the lipolytic enzyme, the process of digestion of fats is especially intense.

Absorption is closely related to parietal digestion and depends on the structure and function of cells in the surface layer of the mucous membrane of the small intestine; it is the main function of the small intestine. Proteins are absorbed in the form of amino acids, but in children of the first months of life, their partial absorption is possible unchanged. Carbohydrates are assimilated in the form of monosaccharides, fats in the form of fatty acids.

The structural features of the intestinal wall and its relatively large area determine in young children a higher absorption capacity than in adults, and at the same time, due to high permeability, an insufficient barrier function of the mucous membrane. The components of human milk are most easily absorbed, the proteins and fats of which are partially absorbed unbroken.

Motor skills in young children are very vigorous, which causes frequent bowel movements. In infants, defecation occurs reflexively; in the first 2 weeks of life up to 3-6 times a day, then less often; by the end of the first year of life, it becomes an arbitrary act. In the first 2-3 days after birth, the child secretes meconium (original feces) of a greenish-black color. It consists of bile, epithelial cells, mucus, enzymes, and swallowed amniotic fluid. On day 4-5, the feces take on a normal appearance. The feces of healthy newborns who are breastfed have a mushy consistency, golden yellow or yellow-greenish color, and a sour smell. The golden-yellow color of feces in the first months of a child's life is explained by the presence of bilirubin, greenish - biliverdin. In older children, the stool is decorated, 1-2 times a day.

The intestines of the fetus and newborn are free of bacteria for the first 10-20 hours. The formation of the microbial biocenosis of the intestine begins from the first day of life, by the 7-9th day in healthy full-term babies receiving breastfeeding, a normal level of intestinal microflora with a predominance of B. bifidus is achieved, with artificial feeding - B. Coli, B. Acidophilus, B Bifidus and enterococci.

The pancreas is a parenchymal organ of external and internal secretion. In a newborn, it is located deep in the abdominal cavity, at the level of the X-th thoracic vertebra, its length is 5-6 cm. In young and older children, the pancreas is located at the level of the I-th lumbar vertebra. The gland grows most intensively in the first 3 years and in puberty. At birth and in the first months of life, it is insufficiently differentiated, abundantly vascularized and poor in connective tissue. In a newborn, the head of the pancreas is most developed. At an early age, the surface of the pancreas is smooth, and by the age of 10-12, tuberosity appears, due to the release of the boundaries of the lobules.

The liver is the largest digestive gland. In children, it is relatively large: in newborns - 4% of the body weight, while in adults - 2%. In the postnatal period, the liver continues to grow, but more slowly than body weight.

Due to the different rate of increase in the weight of the liver and body in children from 1 to 3 years of age, the edge of the liver comes out from under the right hypochondrium and is easily palpable 1-2 cm below the costal arch along the mid-clavicular line. From 7 years in the supine position, the lower edge of the liver is not palpable, and along the midline it does not go beyond the upper third of the distance from the navel to the xiphoid process.

The liver parenchyma is poorly differentiated, the lobular structure is revealed only by the end of the first year of life. The liver is full-blooded, as a result of which it rapidly increases with infection and intoxication, circulatory disorders and is easily reborn under the influence of unfavorable factors. By the age of 8, the morphological and histological structure of the liver is the same as that of adults. The role of the liver in the body is varied. First of all, it is the production of bile, which is involved in intestinal digestion, stimulates the motor function of the intestine and sanitizes its contents. Bile secretion is noted already in a 3-month-old fetus, but bile formation at an early age is still insufficient.

The liver stores nutrients, mainly glycogen, as well as fats and proteins. As needed, these substances enter the bloodstream. Separate cellular elements of the liver (stellate reticuloendothelial cells, or Kupffer's cells, portal vein endothelium) are part of the reticuloendothelial apparatus, which has phagocytic functions and is actively involved in the metabolism of iron and cholesterol.

The liver performs a barrier function, neutralizes a number of endogenous and exogenous harmful substances, including toxins from the intestines, and takes part in the metabolism of drugs. Thus, the liver plays an important role in carbohydrate, protein, bile, fat, water, vitamin ( A, D, K, B, C) metabolism, and during intrauterine development it is also a hematopoietic organ. metabolism of free bilirubin, formed during hemolysis of erythrocytes.

Features of the gallbladder in children

The gallbladder is located under the right lobe of the liver and has a fusiform shape, its length reaches 3 cm. It acquires a typical pear-shaped shape by 7 months, by 2 years it reaches the edge of the liver.

The main function of the gallbladder is the accumulation and secretion of hepatic bile. The composition of the bile of a child differs from that of an adult. It contains little bile acids, cholesterol, salts, a lot of water, mucin, pigments. In the neonatal period, bile is rich in urea. In the child's bile, glycocholic acid predominates and enhances the bactericidal effect of bile, and also accelerates the separation of pancreatic juice. Bile emulsifies fats, dissolves fatty acids, improves peristalsis.

With age, the size of the gallbladder increases, bile of a different composition begins to be secreted than in young children. The length of the common bile duct increases with age.

For children in the first months of life, nutrients that come with the mother's milk and are digested due to the substances contained in the human milk itself are of decisive importance. With the introduction of complementary foods, the mechanisms of the child's enzyme systems are stimulated. The absorption of food ingredients in young children has its own characteristics. Casein is first curdled in the stomach under the influence of rennet. In the small intestine, it begins to break down into amino acids, which are activated and absorbed.

The digestion of fat depends on the type of feeding. Cow's milk fats contain long-chain fats that are degraded by pancreatic lipase in the presence of fatty acids.

Fat absorption occurs in the end and middle sections of the small intestine. The breakdown of milk sugar in children occurs in the border of the intestinal epithelium. Human milk contains lactose, cow's milk contains lactose. In this regard, with artificial feeding, the carbohydrate composition of food is changed. Vitamins are also absorbed in the small intestine.

3 ... Prevention of gastrointestinal disorders

1. Rational and regular nutrition

· Diet, that is, the adaptation of the nature of the diet, the frequency and frequency of food intake to the daily rhythms of work and rest, to the physiological laws of the gastrointestinal tract. The most rational is four meals a day at the same hours of the day. The interval between meals should be 4-5 hours. This achieves the most uniform functional load on the digestive apparatus, which contributes to the creation of conditions for the complete processing of food. An evening meal of easily digestible food is recommended no later than 3 hours before bedtime. Dry food, snacks, and a plentiful evening meal have an unfavorable effect.

· Balanced nutrition, providing daily intake of foods containing proteins, fats, carbohydrates, vitamins, minerals and trace elements. The diet should include: meat, fish, vegetables, fruits, milk and dairy products, herbs, berries, cereals. Restriction in the diet of easily digestible carbohydrates (sweets, baked goods), freeze-dried foods, animal fats, preservatives, dyes. Do not allow the child to consume chips, crackers, carbonated drinks (especially such as: Coca-Cola, Fanta, Pepsi-Cola, etc.), chewing gum.

2. Thoroughly wash your hands with soap and water after: walking on the street, traveling by public transport, going to the toilet; before eating.

3. Compliance with personal hygiene, oral hygiene.

4. Eating well-washed vegetables and fruits, thoroughly fried meat, boiled water.

5. Increasing the body's defenses: air baths, hardening, a healthy lifestyle (adherence to the daily regimen, morning exercises, physical education, a walk (along the SANPin).

6. Dosed physical activity (walking, swimming, tennis, cycling, skating and skiing, etc.).

7. Favorable psychological climate in the family and children's team.

8. Optimal forms of recreation and leisure activities.

9. When bathing a child in a pool, river, sea, explain that it is impossible to swallow water; an adult to ensure that the child does not swallow water.

10. Frequent ventilation of premises.

11. Daily wet cleaning.

12. Carpets should be vacuum cleaned daily, periodically knocked out and wiped with a damp brush, and dry cleaned once a year.

13. Toys in early age group I should be washed twice a day with hot water, a brush, soap or 2% baking soda solution, in specially designated (marked) basins; then - rinse with running water (temperature 37 degrees C) and dry. Toys for older children should be washed daily at the end of the day. Doll clothes are washed and ironed as they get dirty.

14. Annual examination of children for helminthic invasions.

15. Timely appeal for qualified medical care in the event of complaints from a child.

16. Prophylaxis for Chronic gastritis (+ to the above):

Timely identification and treatment of foci of chronic infection;

Measures aimed at eliminating seasonal exacerbations.

Conclusion

Digestion is the process of breaking down food structures into components that have lost their species specificity and are able to be absorbed in the gastrointestinal tract.

Teeth are one of the most important elements of the digestive system. In a child, they usually begin to erupt at the 6-7th month of life.

The digestive organs begin to function long before birth. However, until the end of the intrauterine period, the secretory function of the digestive tract is very weak, since there are no stimuli that stimulate secretion. The gastric juice of a newborn contains little pepsin, but is rich in chymosin, or rennet.

The newborn's stomach is located horizontally in the left hypochondrium. Its capacity is very small. Under the influence of incoming food, the stomach is always somewhat stretched. Repeated stretching of the stomach with each feeding, as well as its physical activity, contribute to the increased growth of the gastric wall.

The small intestine in newborns is only 2 times shorter than in adults. Digestive juices pouring out into the small intestine already in the first days contain all the necessary enzymes that ensure the digestion process. The pancreas is relatively small, and the juice it produces is less active than in the following months.

In terms of quantity and quality, a child's food must meet the characteristics of the digestive tract, satisfy his need for plastic substances and energy.

Bibliography

1. Kabanov A.N., Chabovskaya A.P. Anatomy, physiology and hygiene of preschool children. ? M., Education, 1975.

2. Leontyeva N.N., Marinova K.V. Anatomy and physiology of the child's body. ? M., Education, 1986.

3. Lipchenko V.Ya., Samsuev R.P. Atlas of human anatomy. M., Alliance-B, 1998.

4. Matyushonok M.T., Turik G.G., Kryukova A.A. Physiology and hygiene of children and adolescents. ? Mn., Higher school, 1975.

5. Obreimova N.I., Petrukhin A.S. Fundamentals of anatomy, physiology and hygiene of children and adolescents. ? M., Academy, 2000.

6. Tonkova-Yampolskaya R.V. and other Fundamentals of medical knowledge. ? M., Education, 1986.

7. Chabovskaya A.P. Fundamentals of Pediatrics and Hygiene of Preschool Children. ? M., Enlightenment, 1980

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Chapter 10. Anatomical and physiological features of the digestive system in children. Research methodology. Semiotics and syndromes of defeat

The period of intrauterine formation of the digestive system

Distinguish three periods of bowel rotation:

1) turn by 90 °, the large intestine is on the left, the small intestine is on the right;
2) a 270º rotation, the large and small intestines have a common mesentery;
3) fixation of the intestine ends, the small intestine acquires a separate mesentery.

At the same time, vessels are formed that go to the yolk sac and the intestinal tract. Arteries extend from the aorta. The veins are directed directly to the venous sinus.

In the 10th week the laying of the gastric glands begins, however, their differentiation, both morphologically and functionally, by the time of the birth of a child is not complete.

Between 10th and 22nd During the week of intrauterine development, the formation of intestinal villi occurs - most of the enzymes of membrane digestion appear, but the activation of some of them, for example lactase, occurs only by 38–40 weeks of gestation.

From 16th to 20th week the beginning of the functioning of the system as a digestive organ: the swallowing reflex is already expressed, gastric juice contains pepsinogen, intestinal juice - trypsinogen.

Morphological and physiological features of the digestive system in children especially pronounced in infancy. In this age period, the digestive apparatus is adapted mainly for the assimilation of breast milk, the digestion of which requires the least amount of enzymes (lactotrophic nutrition). A baby is born with a well-pronounced sucking and swallowing reflex. The act of sucking is provided by the anatomical features of the oral cavity of a newborn and an infant. When sucking, the baby's lips tightly grip the mother's nipple with the areola. The jaws squeeze it, and the communication between the oral cavity and the outside air stops. A cavity with negative pressure is created in the child's mouth, which is facilitated by the lowering of the lower jaw (physiological retrognathia) along with the tongue down and back. Breast milk enters the rarefied space of the mouth.

Oral cavity the child is relatively small, filled with tongue. The tongue is short, wide and thick. When the mouth is closed, it comes into contact with the cheeks and hard palate. The lips and cheeks are relatively thick, with well-developed muscles and dense fatty lumps of Bisha. There are roller-like thickenings on the gums, which also play a role in the sucking act.

The mucous membrane of the oral cavity is tender, richly supplied with blood vessels and relatively dry. Dryness is caused by insufficient development of the salivary glands and saliva deficiency in children under 3-4 months of age. The mucous membrane of the oral cavity is easily vulnerable, which should be taken into account when carrying out the toilet in the oral cavity. The development of the salivary glands ends by 3-4 months, and from this time, increased salivation begins (physiological salivation). Saliva is the result of the secretion of three pairs of salivary glands (parotid, submandibular and sublingual) and small glands of the oral cavity. The reaction of saliva in newborns is neutral or slightly acidic. From the first days of life, it contains an amylolytic enzyme. It contributes to the mucousiness of food and foaming; from the second half of life, its bactericidal activity increases.

Login to larynx in an infant, it lies high above the lower edge of the palatine curtain and is connected to the oral cavity; thus, food moves to the sides of the protruding larynx through the communication between the oral cavity and the pharynx. Therefore, the baby can breathe and suck at the same time. From the mouth, food passes through the esophagus into the stomach.

Esophagus. At the beginning of development, the esophagus looks like a tube, the lumen of which is filled due to the proliferation of the cell mass. At 3-4 months of intrauterine development, the laying of glands is observed, which begin to actively secrete. This promotes the formation of a lumen in the esophagus. Violation of the recanalization process is the cause of congenital narrowings and strictures of the esophagus.

In newborns, the esophagus is a fusiform muscle tube lined with a mucous membrane from the inside. The entrance to the esophagus is located at the level of the disc between the III and IV cervical vertebrae, by the age of 2 years - at the level of the IV – V cervical vertebrae, at the age of 12 - at the level of the VI – VII vertebrae. The length of the esophagus in a newborn is 10–12 cm, at the age of 5 years - 16 cm; its width in a newborn is 7–8 mm, by 1 year - 1 cm and by 12 years - 1.5 cm (the size of the esophagus must be taken into account when carrying out instrumental studies).

In the esophagus are distinguished three anatomical constrictions- in the initial part, at the level of the tracheal bifurcation and diaphragmatic. Anatomical narrowing of the esophagus in newborns and children of the first year of life is relatively weak. The peculiarities of the esophagus include the complete absence of glands and insufficient development of muscular-elastic tissue. Its mucous membrane is tender and richly supplied with blood. Outside the act of swallowing, the passage of the pharynx into the esophagus is closed. Peristalsis of the esophagus occurs during swallowing movements. The transition of the esophagus to the stomach in all periods of childhood is located at the level of the X-XI thoracic vertebrae.

Stomach is an elastic saccular organ. Located in the left hypochondrium, its cardial part is fixed to the left of the X thoracic vertebra, the pylorus is located near the midline at the level of the XII thoracic vertebra, approximately in the middle between the umbilicus and the xiphoid process. This situation changes significantly depending on the age of the child and the shape of the stomach. The variability of the shape, volume and size of the stomach depends on the degree of development of the muscle layer, the nature of nutrition, the impact of neighboring organs. In infants, the stomach is horizontal, but as soon as the baby begins to walk, it takes a more upright position.

The capacity of a newborn's stomach is 30–35 ml, by 1 year it increases to 250–300 ml, and by 8 years it reaches 1000 ml.

Stomach mucosa tender, rich in blood vessels, poor in elastic tissue, contains few digestive glands. The muscle layer is underdeveloped. There is a meager secretion of gastric juice with low acidity.

Digestive glands stomach are divided into fundic (main, lining and accessory), secreting hydrochloric acid, pepsin and mucus, cardiac (accessory cells), secreting mucin, and pyloric (main and accessory cells). Some of them begin to function in utero (lining and main), but in general, the secretory apparatus of the stomach in children of the first year of life is insufficiently developed and its functional abilities are low.

The stomach has two main functions– secretory and motor... The secretory activity of the stomach, consisting of two phases - neuro-reflex and chemico-humoral - has many features and depends on the degree of development of the central nervous system and the quality of nutrition.

Gastric juice an infant contains the same components as the gastric juice of an adult: rennet, hydrochloric acid, pepsin, lipase, but their content is reduced, especially in newborns, and increases gradually. Pepsin breaks down proteins into albumins and peptones. Lipase breaks down neutral fats into fatty acids and glycerin. Rennet (the most active enzyme in infants) curdles milk.

Total acidity in the first year of life, 2.5–3 times lower than in adults, and equal to 20–40. Free hydrochloric acid is determined with breastfeeding after 1-1.5 hours, and with artificial feeding - 2.5-3 hours after feeding. The acidity of gastric juice is subject to significant fluctuations depending on the nature and diet, the state of the gastrointestinal tract.

Intestines starts from the pylorus of the stomach and ends with the anus. Distinguish between small and large intestine. The first is subdivided into the short duodenum, the jejunum, and the ileum. The second - on the blind, colon (ascending, transverse, descending, sigmoid) and rectum.

Duodenum the newborn is located at the level of the 1st lumbar vertebra and has a rounded shape. By the age of 12, it descends to the III – IV lumbar vertebra. The length of the duodenum up to 4 years is 7-13 cm (in adults up to 24-30 cm). In young children, it is very mobile, but by the age of 7, adipose tissue appears around it, which fixes the intestine and reduces its mobility.

In the upper part of the duodenum, acidic gastric chyme is alkalized, preparation for the action of enzymes that come from the pancreas and are formed in the intestine, and mixing with bile (bile comes from the liver through the bile ducts).

The jejunum occupies 2/5, and the ileum 3/5 of the length of the small intestine without the duodenum. There is no clear border between them.

Small intestine in children, it occupies an inconstant position, which depends on the degree of its filling, body position, the tone of the intestines and muscles of the peritoneum. Compared to adults, it has a relatively long length, and the intestinal loops lie more compactly due to the relatively large liver and underdevelopment of the small pelvis. After the first year of life, as the small pelvis develops, the location of the loops of the small intestine becomes more constant.

The small intestine of an infant contains relatively many gases, which gradually decrease in volume and disappear by the age of 7 (adults normally have no gas in the small intestine).

To others intestinal features in infants and young children include:

high permeability of the intestinal epithelium;
poor development of the muscle layer and elastic fibers of the intestinal wall;
tenderness of the mucous membrane and a high content of blood vessels in it;
good development of villi and folds of the mucous membrane with insufficient secretory apparatus and incomplete development of nerve pathways.

This contributes to the easy occurrence of functional disorders and favors the penetration into the blood of non-split food constituents, toxic-allergic substances and microorganisms.

After 5–7 years, the histological structure of the mucous membrane no longer differs from its structure in adults.

Colon has a length equal to the height of the child. Parts of the colon are developed to varying degrees. The newborn has no omental processes, the ribbons of the colon are barely outlined, the haustra are absent until the age of six months. The anatomical structure of the colon after 3-4 years of age is the same as in an adult.

Cecum, having a funnel-shaped shape, the younger the child, the higher. In a newborn, it is located directly under the liver. The higher the cecum is located, the more the ascending is underdeveloped. The final formation of the cecum ends by one year.

Appendix in a newborn it has a conical shape, a wide open entrance and a length of 4–5 cm, by the end of 1 year - 7 cm (in adults 9–12 cm). It has greater mobility due to the long mesentery and can be found in any part of the abdominal cavity, but most often it occupies a retrocecal position.

Colon in the form of a rim surrounds the loops of the small intestine. The ascending part of the colon in a newborn is very short (2-9 cm), begins to increase after a year.

Transverse part the colon in a newborn is located in the epigastric region, has a horseshoe shape, length from 4 to 27 cm; by the age of 2, it approaches a horizontal position. The mesentery of the transverse part of the colon is small and relatively long, due to which the intestine can easily move when filling the stomach and small intestine.

Descending part the colon in newborns is narrower than the rest of the colon; its length doubles by 1 year, and by 5 years it reaches 15 cm. It is weakly mobile and rarely has a mesentery.

Sigmoid colon- the most mobile and relatively long part of the large intestine (12–29 cm). Up to 5 years old, it is usually located in the abdominal cavity due to an underdeveloped small pelvis, and then descends into the small pelvis. Its mobility is due to the long mesentery. By the age of 7, the intestine loses its mobility as a result of shortening of the mesentery and the accumulation of adipose tissue around it.

Rectum in children of the first months, it is relatively long and, when filled, can occupy a small pelvis. In a newborn, the rectal ampulla is poorly differentiated, adipose tissue is not developed, as a result of which the ampoule is poorly fixed. The rectum takes its final position by 2 years. Due to the well-developed submucosal layer and poor fixation of the mucous membrane in young children, its loss is often observed.

Anus in children it is located more dorsally than in adults, at a distance of 20 mm from the coccyx.

The process of digestion, which begins in the mouth and in the stomach, continues in the small intestine under the influence of pancreatic juice and bile secreted into the duodenum, as well as intestinal juice. The intestinal secretory apparatus as a whole is formed. Even in the smallest, in the intestinal juice secreted by enterocytes, the same enzymes are determined as in adults (enterokinase, alkaline phosphatase, erepsin, lipase, amylase, maltase, nuclease), but their activity is low.

The duodenum is the hormonal center of digestion and carries out a regulatory effect on the entire digestive system through hormones secreted by the glands of the mucous membrane.

In the small intestine, the main stages of the complex process of cleavage and absorption of nutrients are carried out with the combined action of intestinal juice, bile and pancreatic secretions.

The splitting of food products occurs with the help of enzymes both in the cavity of the small intestine (cavity digestion) and directly on the surface of its mucous membrane (parietal or membrane digestion). The infant has a special cavity intracellular digestion, adapted to lactotropic nutrition, and intracellular, carried out by pinocetosis. The breakdown of food is mainly influenced by the secretion of the pancreas, which contains trypsin (acting proteolytically), amylase (breaks down polysaccharides and converts them into monosaccharides) and lipase (breaks down fats). Due to the low activity of the lipolytic enzyme, the process of digestion of fats is especially intense.

In the large intestine, the absorption of digested food and mainly water is completed, and the remaining substances are broken down under the influence of both enzymes coming from the small intestine and bacteria that inhabit the large intestine. Colon secretion is insignificant; however, it sharply increases with mechanical irritation of the mucous membrane. Feces are formed in the colon.

The motor function of the intestine (motility) consists of pendulum movements that occur in the small intestine, due to which its contents are mixed, and peristaltic movements that promote the movement of the chyme towards the large intestine. The colon is also characterized by antiperistaltic movements that thicken and form fecal masses.

Motor skills in children early age is very energetic, which causes frequent bowel movements. In infants, defecation occurs reflexively; in the first 2 weeks of life up to 3–6 times a day, then less often; by the end of the first year of life, it becomes an arbitrary act. In the first 2-3 days after birth, the child excretes meconium (original feces) of a greenish-black color. It consists of bile, epithelial cells, mucus, enzymes, and swallowed amniotic fluid. On day 4–5, the feces take on a normal appearance. The feces of healthy newborns who are breastfed have a mushy consistency, golden yellow or yellow-greenish color, and a sour smell. The golden yellow color of feces in the first months of a child's life is explained by the presence of bilirubin, greenish - biliverdin. In older children, the stool is formalized, 1-2 times a day.

The intestines of the fetus and newborn are free of bacteria for the first 10–20 hours. The formation of the intestinal microbial biocenosis begins from the first day of life, by the 7-9th day in healthy full-term babies receiving breastfeeding, a normal level of intestinal microflora with a predominance of B. bifidus is achieved, with artificial feeding - B. Coli, B. Acidophilus, B Bifidus and enterococci.

Pancreas- parenchymal organ of external and internal secretion. In a newborn, it is located deep in the abdominal cavity, at the level of the X-th thoracic vertebra, its length is 5–6 cm. In young and older children, the pancreas is located at the level of the I-th lumbar vertebra. The gland grows most intensively in the first 3 years and in puberty. At birth and in the first months of life, it is insufficiently differentiated, abundantly vascularized and poor in connective tissue. In a newborn, the head of the pancreas is most developed. At an early age, the surface of the pancreas is smooth, and by the age of 10–12, tuberosity appears, due to the separation of the boundaries of the lobules.

Liver Is the largest digestive gland. In children, it is relatively large: in newborns - 4% of the body weight, while in adults - 2%. In the postnatal period, the liver continues to grow, but more slowly than body weight.

Due to the different rate of increase in the weight of the liver and body in children from 1 to 3 years of age, the edge of the liver comes out from under the right hypochondrium and is easily palpated 1–2 cm below the costal arch along the mid-clavicular line. From 7 years in the supine position, the lower edge of the liver is not palpable, and along the midline it does not go beyond the upper third of the distance from the navel to the xiphoid process.

The role of the liver in the body is varied. First of all, it is the production of bile, which is involved in intestinal digestion, stimulates the motor function of the intestine and sanitizes its contents. Bile secretion is noted already in a 3-month-old fetus, but bile formation at an early age is still insufficient.

Bile relatively poor in bile acids. A characteristic and favorable feature of the child's bile is the predominance of taurocholic acid over glycocholic acid, since taurocholic acid enhances the bactericidal effect of bile and accelerates the separation of pancreatic juice.

The liver performs a barrier function, neutralizes a number of endogenous and exogenous harmful substances, including toxins from the intestines, and takes part in the metabolism of drugs.

Thus, the liver plays an important role in carbohydrate, protein, bile, fat, water, vitamin (A, D, K, B, C) metabolism, and during intrauterine development it is also a hematopoietic organ.

In young children, the liver is in a state of functional failure, its enzymatic system is especially inadequate, which results in transient jaundice of newborns due to incomplete metabolism of free bilirubin formed during hemolysis of erythrocytes.

Spleen- lymphoid organ. Its structure is similar to the thymus gland and lymph nodes. It is located in the abdominal cavity (in the left hypochondrium). At the heart of the spleen pulp is the reticular tissue that forms its stroma.

Features of the examination of the digestive system. The main symptoms of defeat

Features of collecting anamnesis... A carefully collected anamnesis forms the basis for the diagnosis of diseases of the gastrointestinal tract.

Among the complaints dominated by abdominal pain, dyspeptic syndrome, symptoms of intoxication.

Stomach ache in children, they are a frequent symptom, they often have a recurrent nature, occur in about 20% of children over 5 years of age. The greatest localization of pain in preschool and primary school age - the navel area, which can be noted with various diseases. This is due to the age-related characteristics of the central and autonomic nervous system of the child.

When children develop abdominal pains, each time should be carried out differential diagnosis between the following groups of diseases:

surgical diseases (acute appendicitis, peritonitis, diverticulitis, intestinal obstruction - intussusception, hernia, etc.);
infectious pathology (enterocolitis, hepatitis, yersiniosis, pseudotuberculosis, infectious mononucleosis, etc.);
diseases of the digestive system (at an early age, so-called "infantile colic" are common, at an older age - diseases of the gastroduodenal zone, pathology of the hepatobiliary system and pancreas, bowel disease, etc.);
somatic diseases (pneumonia, myocarditis, urinary tract diseases, manifestations of neuro-arthritic diathesis, Schönlein-Henoch disease, neurocirculatory dysfunction, etc.).

For abdominal pain, find out:

Time of appearance, duration, frequency. Early pain - while eating or within 30 minutes after eating is characteristic of esophagitis and gastritis. Late pains that occur on an empty stomach during the day 30-60 minutes after eating or at night are characteristic of gastritis of the antrum of the stomach, duodenitis, gastroduodenitis, duodenal ulcer;

Connection with food intake and its nature. The intensity of pain can be influenced by the meal itself. With antral gastritis, gastroduodenitis, peptic ulcer of the duodenal bulb after eating, the intensity of pain decreases. But after a while, the pain intensifies again. These are the so-called Moiningan pains. Pain often occurs or worsens when eating spicy, fried, fatty, acidic foods, when eating concentrated, extracted broths, spices, etc.

Place of pain localization. Pain in the epigastric region is characteristic of eosophagitis and gastritis. In pyloroduodenal - antral gastritis, gastroduodenitis, duodenal ulcer. Pain in the right hypochondrium is characteristic of diseases of the biliary tract (dyskinesia, cholecystocholangitis). Girdle pain with predominant localization on the left, above the navel, are noted with pancreatitis. Pain throughout the abdomen is usually observed with enterocolitis. Pain in the right iliac region is characteristic of appendicitis, proximal colitis, ileitis.

Characteristics of pain. Distinguish between paroxysmal, stabbing, persistent, dull, aching and night (with peptic ulcer) pain. In the first year of life, abdominal pain is manifested by general anxiety, crying. As a rule, children twist their legs, which is often the case with flatulence, and after the gas passes, they calm down.

Connection with physical, emotional stress and other factors.

Among the dyspeptic phenomena, the gastric and intestinal forms of disorders are distinguished.

At gastric dyspepsia children are noted: belching, nausea, heartburn, vomiting, regurgitation. They reflect impaired motility of the gastrointestinal tract and are not strictly a specific symptom of any disease.
Belching is a consequence of an increase in intragastric pressure with insufficiency of the cardiac sphincter. It occurs with esophagitis, hiatal hernia, cardia insufficiency, chronic gastritis, gastroduodenitis, peptic ulcer disease. In the 1st year of life in children, due to weakness of the cardiac sphincter, belching with air (aerophagia) is often noted, this may also be due to a violation of the feeding technique.
Nausea in children, it is more often the result of increased intraduodenal pressure. It occurs in diseases of the duodenum (duodenitis, gastroduodenitis, peptic ulcer of the duodenal bulb). Preceded by vomiting.
Heartburn observed with gastroesophageal reflux, esophagitis, due to the throwing of the acidic contents of the stomach into the esophagus.
Vomit- a complex reflex act, during which there is an involuntary ejection of the contents of the stomach through the esophagus, pharynx, mouth outward. Vomiting can be of nervous origin (with damage to the central nervous system, meningitis, intoxication, irritation of the vomiting center with various infections), and with damage to the gastro-duodenal zone (acute and chronic gastritis, gastroduodenitis, peptic ulcer, intestinal infections, foodborne toxicoinfections). With force-feeding, "habitual vomiting" may form. A type of vomiting in children of the first year of life is regurgitation, which occurs without effort, i.e. without tension of the abdominal press. Often, regurgitation occurs in practically healthy children at 1 year of age, but it can be a sign of an incipient intestinal infection. They are also found with a "short" esophagus and achalasia of the cardia. Rarely, in children with intellectual disabilities, rumination occurs - gum, characterized by the fact that the vomit regurgitated into the oral cavity is swallowed by the child again. Vomiting in a fountain - a typical sign of pyloric stenosis, while there is no admixture of bile in the vomit. Intestinal dyspepsia manifested by diarrhea, less often - by constipation, flatulence, rumbling.

In the first 1-2 days of life, healthy newborns excrete meconium - stool, which is a thick, viscous mass of dark olive color, odorless, accumulated in the intestines before childbirth, before the first attachment to the breast. The absence of epithelial cells in meconium may be a sign of intestinal obstruction in a newborn. The admixture of meconium to the amniotic fluid at the beginning of labor indicates intrauterine asphyxia. The type of feces in breastfed babies in the first year of life is mushy, golden-yellow in color with a slightly acidic odor. The number of bowel movements is up to 7 times a day in the first half of the year, and 2-3 times a day in the second.

With artificial feeding, the feces are thicker, putty consistency, light yellow in color, with an unpleasant odor, the number of bowel movements 3-4 times a day for up to 6 months and 1-2 times a day for up to a year. In older children, the stool is shaped (like a sausage), dark brown, does not contain pathological impurities (mucus, blood). The chair is 1-2 times a day. With various diseases, the nature of the stool changes, they are distinguished:

dyspeptic stool, liquid with an admixture of mucus, greens, white lumps, foamy, sour odor (it happens with simple dyspepsia - "fermentative dyspepsia");
"Hungry" stool, scanty, resembles dyspeptic, but thicker, darker (it happens with hypotrophy);
stool for toxic dyspepsia is watery, light yellow in color with an admixture of mucus;
with colienteritis, the stool is liquid, ocher-yellow (less often greenish) with an admixture of mucus and white lumps;
with salmonellosis - the stool is liquid, green (like marsh greens), a small amount of mucus, there is no blood;
with dysentery, the stool is speeded up (up to 15 times), contains a large amount of mucus, pus and streaks of blood, almost no feces, defecation is accompanied by tenesmus;
with typhoid fever, the stool is speeded up (up to 10 times) liquid, fetid, in the form of pea puree, occasionally contains an admixture of bile;
with cholera, the stool is almost continuous (up to 100 times a day), plentiful, in the form of rice water, never contains blood;
with food toxicoinfections, the stool is liquid, frequent, abundant, greenish-yellow in color with an admixture of mucus (rarely streaked with blood);
with amoebiasis, the stool is speeded up, the color of raspberry jelly;
with giardiasis, stool 3-4 times a day, yellow-green color, soft consistency;
with viral hepatitis, the stool is acholic, gray-clay colored, without pathological impurities;
for malabsorption syndromes, polyfecalis is characteristic (when the amount of feces exceeds 2% of the food eaten and the liquid drunk). This syndrome is observed with disaccharide deficiency (lactose and sucrose), celiac disease (gluten intolerance, gliadin), cow's milk protein intolerance, and chronic pancreatitis;
melena (black homogeneous stool), occurs with bleeding in the upper gastrointestinal tract (esophagus, stomach, duodenum, small intestine);
Red blood in the stool appears with bleeding in the terminal parts of the ileum and colon (with intestinal polliposis, intussusception, Crohn's disease, at 2-3 weeks of typhoid fever, with cracks in the anus (where the blood is separate from the feces);
constipation (stool retention for more than 48 hours) is of organic and functional origin. If a newborn child has no stool for 1-3 days from birth, one should think about congenital anomalies of intestinal development (megacolon, Hirschsprung's disease, megasigma, atresia of the anus, etc.). At an older age, constipation is noted with colitis, hypothyroidism and other conditions.

Flatulence- bloating, like rumbling, occurs as a result of a violation of the absorption of gases and liquid contents in the terminal ileum and the proximal colon, it is observed more often with enterocolitis, intestinal dysbiosis.

Reveal signs of intoxication:

the presence of lethargy, fatigue, loss of appetite;
increased body temperature;
changes in the leukocyte formula, acute phase reactions of the blood.

It is extremely important to establish the relationship between the above syndromes. An important role in the development of diseases is played and needs to be clarified when taking anamnesis:

Inspection... In older children, the examination begins with the oral cavity, and in young children, this procedure is carried out at the end of the examination, in order to avoid a negative reaction and anxiety. Pay attention to the color of the oral mucosa, pharynx and tonsils. In healthy children, the mucous membrane is pale pink, shiny. With stomatitis, the mucous membrane is locally hyperemic, the shine disappears (catarrhal stomatitis), and defects of the mucous membrane in the form of aphthous or ulcers (aphthous or ulcerative stomatitis) can also be found. Determine the symptom of Filatov - Koplik (the mucous membrane of the cheeks against the small molars, less often the gums, covered with a bloom in the form of semolina), which indicates a measles prodrome. You can find inflammatory changes in the gums - gingivitis, or lesions of the tongue - glossitis (from catarrhal to ulcerative necrotic). When examining the tongue, it is revealed that it is clean (normal) or coated (for diseases of the gastrointestinal tract). Plaque on the tongue can be located over the entire surface or only at the root of the tongue. Have a different color: white, gray or dirty, and density: be thick or shallow. The appearance of the tongue is peculiar for various diseases: with anemia, atrophy of the papillae is noted, and it resembles a "polished" tongue; with scarlet fever - raspberry color, especially the tip; with acute intestinal and other infections, the tongue is dry, coated with a bloom; with exudative-catarrhal diathesis, the language is "geographical". With a strong cough, accompanied by reprisals, ulcers appear on the mucous membrane of the frenum of the tongue, as it is traumatized on the lower anterior incisors. Find out the condition of the teeth (formula, caries, defects, enamel, bite anomalies).

Examination of the abdomen ... First of all, attention should be paid to the participation in the act of breathing of the abdominal wall. With local peritonitis (acute appendicitis, cholecystitis), movements are limited, and with diffuse peritonitis, the anterior abdominal wall does not take part in breathing, it is tense. In children of the first months with pyloric stenosis, gastric peristalsis in the epigastric region in the form of an hourglass can be noted. Intestinal peristalsis is observed with intestinal obstruction.

Normally, the anterior abdominal wall does not go beyond the plane, which, as it were, is a continuation of the chest.

Enlargement of the abdomen in volume observed in obesity, flatulence, ascites, pseudoascitis, chronic tuberculous peritonitis, significant enlargement of the liver and spleen, tumors of the abdominal cavity, intestinal anomalies (megacolon). With hepatosplenomegaly, the abdomen increases in the upper sections. With tumors, there is an asymmetry of the abdomen. The retraction of the abdominal wall is characteristic of acute peritonitis, it happens with severe exhaustion, dysentery, tuberculous meningitis.

A pronounced venous network on the anterior abdominal wall in newborns can be a sign of umbilical sepsis. In children older than a year, a pronounced venous network often indicates portal hypertension (intrahepatic - with cirrhosis of the liver, extrahepatic - with thrombosis of v.portae), while there is a difficulty in the outflow of blood through the v.portae system and the inferior vena cava. Swelling of the anterior abdominal wall in newborns is noted with umbilical sepsis, sometimes septic enterocolitis, and in children over a year old - with ascites and tuberculous peritonitis.

Palpation of the abdomen. When examining the abdominal organs, their topography is important when projected onto the anterior abdominal wall. For this purpose, it is customary to distinguish between different areas of the abdomen. By two horizontal lines, the abdominal cavity is conditionally divided into three sections: epigastrium, mesogastrium and hypogastrium. The first division line connects the X-th ribs, and the second - the iliac spines. Two vertical, running along the outer edge of the rectus abdominis muscles, additionally divide the abdominal cavity into 9 parts: left and right hypochondrium; proper epigastric region (epigastrium), left and right lateral regions (flanks), umbilical, left and right iliac regions, suprapubic. Conditionally produce the division of the abdomen into sections : epigastric, mesogastric and hypogastric. Epigastric region is divided into the central zone - the epigastrium, as well as the left and right hypochondria. Mesogastrium - on the umbilical zone, left and right flanks. Hypogastrium- on the suprapubic zone, left and right iliac regions.

For correct palpation, the doctor sits to the right of the patient, facing him. The child should lie on his back with legs slightly bent at the hip and knee joints. The arms should be extended along the torso, the head level with the torso, it is desirable to distract the child.

Superficial or approximate palpation is carried out by light pressure on the anterior abdominal wall, and all parts of the abdomen are sequentially examined, moving clockwise or counterclockwise, depending on the presence and localization of abdominal pain. Palpation should be started from the area that does not hurt. Both or one hand is placed with the palmar surface on the abdominal wall, pressure is carried out with 2-3-4-5 fingers of the palpating hand. This method reveals the tension of the abdominal wall, tumor formations, soreness.

The tension of the anterior abdominal wall can be active and passive. To eliminate active stress, it is necessary to divert the child's attention. It can be used as a distraction technique to change the posture, transfer the child to a sitting position. At the same time, active tension disappears during palpation, while passive tension remains. In children during the neonatal period, the umbilical ring and umbilical vessels should be palpated.

Areas of skin sensitivity are of great importance when examining painful zones - Zakharyin - Geda zones... When examining areas of hyperesthesia in older children, you should slide over the skin, lightly stroking the skin with both hands in symmetrically located areas to the right and left of the white line of the abdomen.

There are the following zones of hyperesthesia :

Choledochoduodenal zone- the right upper square (the area bounded by the right costal arch, the white line of the abdomen and the line passing through the navel perpendicular to the white line of the abdomen).
Epigastric zone- occupies the epigastrium (the area of the abdomen above the line connecting the right and left costal arches).
Shoffard zone, which is located between the white line of the abdomen and the bisector of the upper right square.
Pancreatic zone- a zone in the form of a strip that occupies the mesogastrium from the navel to the spine.
Painful area of the body and tail of the pancreas- occupies the entire upper left square.
Appendicular zone- bottom right square.
Sigmal zone- lower left square.

With the help of superficial palpation, the asymmetry of the thickness of the subcutaneous tissue is also determined, for which, at the level of the navel on both sides, the skin and subcutaneous tissue are gathered into folds with the first and second fingers. After superficial orientational palpation, they proceed to deep sliding, topographic methodological palpation according to Obraztsov and Strazhesko.

Deep palpation is carried out in a specific order: the sigmoid colon and the descending colon, the blind, the ascending colon, the end of the ileum, the appendix, the transverse colon. Deep palpation ends with palpation of the pancreas, liver and spleen.

Palpation of the large intestine... Palpation of the sigmoid colon - the examiner's right hand is placed flat with slightly bent fingers on the left iliac region so that the terminal phalanges of the fingers are located perpendicular to the longitudinal axis of the sigmoid colon. During inhalation, with a superficial movement of the fingers, the skin moves slowly, forming a fold, from the outside to the inside and from the bottom up. During exhalation, the fingers sink as deeply as possible, and then by moving the hand from the inside to the outside and from top to bottom, together with the skin of the anterior abdominal wall, they roll through the intestine. Typically, the sigma is located along the bisector of the lower left quadrant.

Determine the consistency, mobility, elasticity, soreness of the sigmoid colon. The limited mobility of the sigmoid can be caused by an inflammatory process (perisigmoiditis), as well as a short mesentery. A dense, thin, painful intestine is palpable with spastic colitis, dysentery. Thicker than normal, the S-shaped intestine happens when it is filled with feces; with atony, with the development of the pericolytic process. A very dense sigmoid colon is observed in tuberculosis, ulcerative colitis.

Palpation of the cecum- The palpation technique is the same as for the sigmoid colon, but is performed in the right ileal region. The direction of the cecum from the right from top to bottom to the left. Simultaneously with the cecum, the ascending intestine is palpated.

The displacement of the cecum is several centimeters. Limitation of displacement can be caused by an inflammatory process (perityphlitis) or a congenital short mesentery. Soreness on palpation indicates an inflammatory process and occurs in various pathologies (influenza, dysentery, typhoid fever, tuberculosis, etc.). The dense cecum is palpated with a delay in feces (fecal stones), with an ulcerative-inflammatory process.

Palpation of the terminal segment of the ileum carried out following the palpation of the cecum. Palpation of other parts of the small intestine is difficult due to the resistance of the abdominal press. The researcher puts his hand at an obtuse angle and probes from the inside outwards and from top to bottom. A feature of palpation of the end section is its peristalsis under the palpating hand.

With a spastic contraction, the ileum is dense, thin. With enteritis, pain and rumbling are noted (because gas and liquid are present). With terminal ileitis (Crohn's disease), the terminal segment is painful and thickened. A lumpy, uneven surface of the ileum can be observed in patients with typhoid fever, lymphogranulomatosis, lymphosarcomatosis. To distinguish a lesion of the cecum from terminal ileitis or mesoadenitis, it is necessary to palpate the cecum with the right hand, and palpate the ileum with the left hand medially to the displaced cecum. If the greatest pain is noted in the lateral region, one can think of a lesion of the cecum or appendix. With mesoadenitis, the greatest pain occurs medially (under the left hand).

Palpation of the transverse colon done with two hands. The fingers are set parallel to the bowel movement 2-3 cm above the navel on both sides in the area of the outer edge of the rectus muscles, slightly shifting them to the center and immersing the fingers deep into the abdominal cavity on exhalation. Then a sliding movement of the hands is made from top to bottom.

On palpation of any part of the large intestine it is necessary to note the following properties of the palpable section: localization, shape, consistency, size, surface condition, mobility, the presence of rumbling and soreness.

In healthy children, the intestine is palpated in the form of a soft cylinder. Rumbling indicates the presence of gas and liquid.

Dense and overcrowded bowel occurs with retention of feces (constipation), painful - with colitis. The presence of a spasmodically contracted, with separate places of compaction, the transverse colon indicates ulcerative colitis. With atony, the intestine is palpated in the form of a soft cylinder with flaccid walls. With megacolon, the transverse colon is greatly enlarged and can occupy almost the entire abdominal cavity.

Palpation of the stomach possible only with deep palpation, but not always. The greater curvature is palpable slightly above the navel. The correctness of palpation of the stomach and its location are assessed using the splash phenomenon, as well as percussion.

Descent of the greater curvature of the stomach is observed with gastroptosis, expansion and atony of the stomach, with pyloric stenosis. Palpation of the pylorus is of particular importance for the diagnosis of pyloric stenosis. An infant is given expressed milk or tea, and at this time the pylorus is palpated on the right - at the edge of the liver and the outer edge of the right abdominal muscle, trying to penetrate with your fingertips to the posterior abdominal wall. In the early stages of pyloric stenosis, a thickened pylorus is found under the rectus abdominis muscle on the right. With a significant increase in the stomach, it shifts laterally and downward. Palpation reveals a dense, fusiform, mobile formation up to 2–4 cm long.

Palpation of the pancreas according to the Groot method, it is carried out with the child lying down. The doctor's right hand, clenched into a fist, is brought under the patient's lower back. The patient's legs are bent at the knees. The examiner's fingers penetrate the abdominal cavity between the navel and the left hypochondrium (the outer edge of the left rectus abdominis muscle in the left upper quadrant). Palpation is carried out on exhalation (abdominal muscles are relaxed) towards the spinal column. The pancreas is felt in the form of a strand with a diameter of about 1 cm obliquely overlapping the vertebral column. With its inflammation, the patient experiences pain radiating to the back, spine. Diagnostic value, as already indicated, is the definition of the Shoffard pain zone, where the body of the pancreas is projected, as well as pain points.

Desjardins point- a painful point of the head of the pancreas, located on the border of the middle and lower third of the bisector of the right upper quadrant.

Mayo - Robson point- the painful point of the tail of the pancreas, located on the border of the upper and middle third of the bisector of the upper left quadrant.

Kacha point- the painful point of the pancreas, located on the left edge of the rectus abdominis muscle 4–6 cm above the navel.

Obraztsov's symptom- soreness and rumbling on palpation in the right iliac region.

Palpation of the liver... Until the age of three, the liver in children in a calm position protrudes from under the edge of the costal arch along the midclavicular line by 2–3 cm, and at the age of 5–7 years - by 1–2 cm. At the height of inspiration, you can feel the lower edge of the liver in children and at an older age. But usually in healthy children over 7 years of age, the liver is not palpable. There are two main types of liver palpation: sliding (sliding) palpation of the liver according to Strazhesko and the second - according to Strazhesko-Obraztsov. The position of the patient is lying on his back with slightly bent legs, the pillow is removed. The arms are either extended along the torso or lie on the chest. The fingers of the doctor's palpating hand form one line - parallel to the lower border of the liver and make a slight sliding movement from top to bottom. Sliding movements should touch the entire surface of the liver accessible to palpation. Especially often, the sliding technique of palpation of the liver is used in infants and young children.

Then go to palpation of the liver by the Obraztsov-Strazhesko method... The right (palpating) hand is placed flat on the area of the right half of the abdominal wall at the level of the navel or below. With the left hand, they cover the right half of the chest in the lower section. Leaving the right hand deeply inserted into the abdominal cavity as you exhale, ask the child to take a deep breath in place. When inhaling, the palpating hand is withdrawn from the abdominal cavity in the forward and upward direction. In this case, the lower edge of the liver, sliding down, seeks to bypass the palpating fingers. At this moment, the shape and shape of the edge of the liver, its consistency and soreness are determined.

In a healthy child, the lower edge of the liver is painless, sharp and softly elastic. With various diseases, the density of the lower edge of the liver may increase, and its soreness appears.

Shrinking of the liver characteristic of its acute dystrophy (with viral hepatitis B), first the upper dome of the liver is flattened, and then its lower edge. With the predominance of dystrophic processes in the cirrhotic liver, it can also decrease in size and not be palpable. The disappearance of hepatic dullness occurs when an ulcer of the duodenum or stomach perforates.

A dense hard edge of the liver, up to stony, is noted with cirrhosis, with congenital fibrocholangiocystosis, leukemia, lymphogranulomatosis, while in many cases the surface of the liver is uneven. A smooth, even, soft surface of the liver with a rounded edge, rarely painful on palpation, occurs with acute stagnation of blood, due to cardiovascular failure, with hepatitis, cholangitis, cholecystocholangitis. Sharp soreness when palpating the surface of the liver is characteristic of perihepatitis (with the involvement of the liver capsule in the inflammatory process).

Gall bladder in children it is not palpable. In diseases of the gallbladder (cholecystitis), pain in the area of its projection is determined (T. Kera).

On palpation, a number of symptoms are determined, indirectly indicating damage to the biliary tract or other organs:

soreness on inspiration at the Kera point or vesicular point (with pathology of the gallbladder) - the place of intersection of the outer edge of the rectus abdominis muscle with the right costal arch;
Murphy's symptom - the appearance of sharp pain on palpation at the moment of inhalation in the gallbladder (the place of intersection of the outer edge of the rectus abdominis muscle with the costal arch);
arenicus symptom (Mussey symptom) - soreness when pressing between the legs of the right sternocleidomastoid muscle;
Boas's symptom - pain when pressing in the area of the transverse processes of the 8th thoracic vertebra on the right on the back;
Openchowski's symptom - pressure in the area of spinous processes of 10-11-12 thoracic vertebrae on the back, soreness is characteristic of gastric ulcer and duodenal ulcer.

In differential diagnosis to exclude surgical pathology, the symptoms of "acute abdomen" are determined:

Shchetkin-Blumberg symptom- the occurrence of acute pain in the abdomen at the time of rapid withdrawal of the palm from its surface after gentle pressing - speaks of irritation of the peritoneum in the investigated area;
Rovsing's symptom- increased pain in the caecum (in the case of appendicitis) with jerky pressure in the left iliac region;
Sitkovsky symptom- increased pain in the right iliac region (with appendicitis) when the patient turns to the left side.

Percussion method It is used to determine the boundaries of the liver, which is carried out along three lines: anterior axillary, midclavicular and anterior median. The upper border of the liver is determined by percussion from top to bottom along the linea axillaris anterior dextra until the transition of a clear pulmonary sound to a dull (hepatic) sound, normally on the IV – VII rib. Along the linea medioclavicularis dextra on the V – VI rib. The upper border of the liver along the anterior midline is roughly determined - it is located at the level of continuation along the corresponding intercostal space of the upper border of the liver, determined by the midclavicular line. The lower border of the liver is determined along the same lines. The finger-plessimeter is placed parallel to the borders of the liver, percussed in the direction from clear to dull sound, from bottom to top. Measure the distance between the upper and lower borders of the liver along all 3 lines.

In young children, the upper edge of the liver is determined by the method quiet percussion, and the lower one is better to define by palpation along the indicated lines. And if the bottom edge is not palpable, then it is determined by percussion. As already noted, depending on age, the lower edge of the liver in children can protrude along the midclavicular line 1-2 cm below the edge of the costal arch, and along the anterior midline it does not go beyond the upper third of the line connecting the xiphoid process with the navel.

For more accurate control of changes in the size of the liver in dynamics, in children from 5-7 years of age, the method for determining the size of the liver according to Kurlov is used.

Percussion of the borders of the liver and measurement of its size according to Kurlov is carried out along three lines:

along the midclavicular from above to the upper border of the liver, which in children is located on the V-VI rib, below the level of the navel (or below) towards the costal arch;
along the anterior midline - from above to the upper border of the liver, which is located at the beginning of the xiphoid process and from below from the navel up to the upper third of the distance from the end of the xiphoid process to the navel;
along the oblique line - the left costal arch, percussion along it from the bottom up from the left midclavicular line towards the sternum.

The liver measurement results record looks like this: 9x8x7 ± 1cm. Depending on the age of the child, the size of the liver may be smaller and the main landmarks should be the upper border - 5-6 ribs and the lower border - the costal arch.

With various diseases, the dynamics of the size of the liver changes. So, with right-sided exudative pleurisy, the lower edge of the liver shifts down, and with flatulence, ascites - up.

Percussion can reveal the following pathological symptoms:

Ortner-Grekov symptom - tapping with the edge of the palm along the right costal arch is painful with damage to the gallbladder or liver;
Mendel's symptom - tapping on the anterior surface of the abdomen in the epigastric region. The patient should take a deep abdominal breath in order to bring the stomach closer and make it more accessible for examination. Mendel's symptom allows you to topographically determine the location of a stomach ulcer, if any;
Frenkel's symptom - nausea and back pain with percussion along the xiphoid process of the sternum (positive for acute cholecystitis, gastritis, peptic ulcer).

It is also necessary to conduct a study to determine the presence of free fluid in the abdominal cavity. Free fluid in the abdominal cavity is determined by palpation using undulation. To do this, the left hand is placed flat on the lateral surface of the abdominal wall on the right, and with the fingers of the right hand, a short blow is applied to the abdominal wall on the other side. This blow causes vibrations of the liquid, which are transmitted to the other side and are perceived by the left hand in the form of a so-called wave. In order to make sure that the wave is transmitted through the liquid and not along the abdominal wall or intestinal loops, it is recommended that the doctor's assistant put his palm with an edge on the middle of the abdomen and press lightly, this technique eliminates the transmission of the wave along the abdominal wall or intestines.

Percussion can also determine the presence of fluid in the abdominal cavity. For this, the sick child lies on his back. Percussion is performed along the anterior abdominal wall in the direction from the navel to the lateral parts of the abdomen (flanks). Research is conducted using mediocre percussion. The pessimeter finger is located parallel to the white line of the abdomen in the navel and gradually moves to the flanks, first to the right, then to the left, while percussion blows are applied to the plessimeter with the middle finger of the right hand. The presence of bilateral shortening in the area of the flanks may indicate the presence of free fluid in the abdominal cavity.

For the differential diagnosis of ascites and dullness in the abdominal cavity due to other reasons (full intestine, swelling, etc.), it is necessary to turn the child on its side and perform abdominal percussion in the same sequence. If the dullness in the superior flank disappears, one can think of fluid in the abdominal cavity, if it remains, the shortening is due to another reason.

On abdominal auscultation in a healthy child, intestinal motility can be heard, the intensity of these sound phenomena is low. With pathology, sound phenomena can increase or decrease and disappear.

With help mixed method research - auscultation and percussion (auscultafriction) can determine the boundaries of the stomach. The stethoscope is placed in the epigastric region - the region of the stomach and stroking with one finger from top to bottom along the white line of the abdomen from the xiphoid process to the navel. In the area of the stomach, the audibility of the sound in the stethoscope is sharply increased. The zone of best listening corresponds to the boundaries of the stomach.

The method of examining the stomach, called "Splash noise". Its essence is that with a concussion of the stomach, where air and liquid are located at the same time, a kind of noise occurs. When the blows are applied in the area where there is no stomach, the splashing noise will stop. This technique before the X-ray examination allows you to diagnose gastroptosis.

Features of laboratory and instrumental examination of the gastrointestinal tract. The volume of the required laboratory and instrumental examination is determined individually, taking into account the nature of the alleged disease. When studying the esophagogastroduodenal zone, various methods are used.

Fractional gastric intubation - continuous aspiration of fasting, basal and stimulated (histamine 0.008 mg / kg, pentagastrin 6 μg / kg) gastric secretions with an assessment of the volume, titration acidity and calculation of the debit hour. A fractional study of gastric juice is carried out on an empty stomach. Take a probe (the size depends on the age of the child), measure the length from the corner of the mouth to the navel (plus 1 cm), make a mark. Help the child to swallow the tube. Immediately after swallowing, gastric juice is sucked off. First, the entire contents of the stomach are aspirated - a lean or "O" portion. Then the juice is slowly sucked off within one hour: 4 portions every 15 minutes. This is the basal secretion. At the end of the hour, a 0.1% histamine solution or 0.25% petagastrin solution is injected subcutaneously (as an irritant). After 5 minutes, 4 portions are sucked off again for 1 hour every 15 minutes and stimulated secretion is obtained. Thus, 9 portions are sent to the laboratory, where they are filtered and titrated with 0.1% sodium hydroxide solution in the presence of indicators to determine the concentration of hydrogen ions and the acid-forming function of the stomach. The method for studying the enzyme-forming function of the stomach is based on determining the proteolytic activity of gastric contents in relation to the protein substrate. Indicators of gastric secretion are given in table. 24.

Table 24. Normal indices of gastric secretion in children over 5 years of age

Indicators	Basal	Stimulated by meat broth	Stimulated by pentagastrin
Volume (ml / h)
Free hydrochloric acid (titre units)
Total acidity (titer units)
Acid production (HCl flow rate)
body pH / alkaline time (min.)
antrum pH				Various quantity
Mucus, epithelium, worm eggs	Absent
Leukocytes	Single

Changes in the coprogram make it possible to distinguish a number of scatological syndromes (Table 28).

Table 28. Scatological syndromes in children

	Macro- and microscopic data of feces
Gastrogenic	Unchanged muscle fibers, intracellular starch, connective tissue
Pyloroduodenal	Unchanged muscle fibers, connective tissue, plant fiber
Pancreatic insufficiency	Liquid, greasy, yellow-gray stool, neutral fat, altered muscle fibers, extracellular starch
Lack of bile secretion	The stool is gray. Soaps and crystals of fatty acids, no reaction to stercobilin
Enteral	Lots of epithelium, crystals of fatty acids, extracellular starch
Ileocecal	Mucus, an abundance of digestible fiber, starch grains, iodophilic flora
Colitis	Mucus, leukocytes, erythrocytes, epithelium

D-xylose test - reflects the activity of absorption in the intestine, assessed by urinary excretion for 5 hours given through the mouth of D-xylose (norm: in children of the 1st year of life - more than 11%, in children older than a year - more than 15%).

Lactose- (sucrose-, maltose-, isomaltose-) tolerance test - identification of violations of the cleavage or absorption of hydrolysis products of disaccharides by studying the dynamics of glycemia after oral loading with this disaccharide (at a dose of 50 g / m 2).

Hydrogen breath test - detection of impaired fermentation in the intestine of carbohydrates by increasing the hydrogen content in the exhaled air by more than 0.1 ml / min.

Thin layer chromatography sugar in urine allows you to determine the qualitative nature of mellituria;

Enterokinase activity in the contents of the small intestine - normally it is 130–150 units / ml, in case of violation of the enzyme production, the indicator decreases.

Radioisotope method estimates of the excretion of albumin labeled with iodine-31 with feces - normally, the excretion is no more than 5% of the amount of the isotope taken; in case of malabsorption, the indicator increases.

Daily excretion of fat with feces (according to Van de Kamer ) - against the background of taking 80 - 100 g of fat per day, the normal excretion does not exceed 3 g; when hydrolysis and absorption are disturbed, fat excretion increases.

Immunohistological and enzymohistological methods studies of biopsies of the mucous membrane of the proximal small intestine.

Small intestine perfusion with carbohydrate solutions, protein and fat emulsions - detection of violations of enzymatic degradation of the substrate and impaired absorption of products of its hydrolysis.

Colonoscopy, sigmoidoscopy - endoscopy of the lower intestine: allows you to detect inflammatory and destructive changes, pathological formations of the mucous membrane, structural anomalies.

Irrigography - X-ray contrast study of the colon. Allows you to assess the relief of the mucous membrane, intestinal motility, identify abnormalities, tumors, etc.

Bacteriological examination of feces - assessment of the biocenosis of the large intestine, identification of dysbiosis.

Anamnesis and examination data allow a preliminary diagnosis to be formulated. Taking into account laboratory and instrumental results, a clinical diagnosis of the disease is established.

Features of the gastrointestinal tract of a newborn child largely determine the specificity of lesions of the digestive system.

The oral cavity is relatively small. The sucking act is facilitated by the anatomical formations of the oral cavity: duplication of the oral mucosa located along the alveolar arches (Robin-Mazhito fold), transverse folding of the lips (Lushka-Pfaundler rolls), accumulation of fat in the thickness of the cheeks (cheek fatty body). The mucous membrane of the oral cavity is well vascularized, somewhat dry due to a small amount of saliva

The saliva of a newborn does not play a significant role in digestion due to the low content of amylase and the almost complete absence of mucin and maltase. The richest in enzymes is the saliva of the parotid glands, to a lesser extent - the saliva of the submandibular and sublingual glands.

The esophagus reaches 10-12 cm in length and up to 8 mm in width. The mucous membrane of the esophagus has a well-pronounced folding, leading to the complete closure of its walls at rest. Physiological constrictions are poorly expressed. The entrance to the stomach gapes. The latter is due to many reasons, the main of which are the imperfection of the nervous apparatus and the special topographic-anatomical relationship of the esophagus and stomach in this period.

The innervation of the cardiac esophagus is carried out by neuroblasts at an early stage of development, which weakly provide the closure of the cardiac foramen. During the first months of a child's life, neuronal differentiation continues in the esophagus, which ends only by the 20th year of life.

The abdominal part of the esophagus in newborns is located 1-2 vertebrae higher than in older children, the weak development of the mucous and muscular membranes of the esophagus and the cardiac part of the stomach leads to insufficient expression of the His angle, which is formed by the wall of the abdominal part of the esophagus and the adjacent wall of the fundus of the stomach ... The circular layer of the muscles of the cardiac part of the stomach is poorly developed. As a result, the fold of the mucous membrane, protruding into the lumen of the esophagus and preventing the return of food from the stomach, is almost not expressed. The legs of the diaphragm are loosely covering the esophagus. All this together contributes to regurgitation and vomiting in newborns, especially with an increase in intragastric pressure.

The stomach is more often rounded. The physiological capacity of the stomach on the first day is 7-10 cm 3, by the 10th day it reaches 90 cm 3. It was found that the stomach grows more intensively than other organs. The enlargement of the stomach during the first year of life is mainly due to muscle fibers. In the future, the number of elastic fibers in the muscle tissue increases, which contributes to the improvement of its motor function. In premature babies, there is a weak development of the muscles of the cardiac part of the stomach.

The mucous membrane of the stomach is relatively thicker. Its area is about 40-50 cm 2. The formation of the secretory function begins already at the 8-9th week of intrauterine life. By the time of birth, the process of differentiation of the glandular apparatus of the stomach is not complete.

The digestive capacity of the stomach is weak, which is determined by insufficient production of hydrochloric acid by the parietal cells of the mucous membrane. The pH of the gastric contents ranges from 4 to 6. During breastfeeding, a larger amount of hydrochloric acid could interfere with the absorption of certain milk components, for example, γ-globulins, some of which are absorbed in the intestines.

The stomach of a newborn produces pepsin, cathepsin, chymosin (rennet) and lipase. The most important are cathepsin and chymosin. Cathepsin has the ability to digest protein to peptones and albumosis in a less acidic environment that the gastric contents of a newborn have. Chymosin curdles casein in milk. The peculiarity of the action of this enzyme is the ability to produce a cleaving effect in a weakly acidic, neutral or even slightly alkaline environment.

Thus, gastric digestion in a newborn is carried out with a weakly acidic reaction. Its effectiveness is determined by specific enzymes characteristic of children in the first weeks of life.

The intestines of a newborn are relatively longer than that of an adult. Its total length reaches 330-360 cm. The ratio of the length of the large intestine to the length of the small intestine is approximately 1: 6, which indicates the role of the latter in the processes of digestion.

The duodenum is often ring-shaped. The place of its transition to the lean one is at the Li - Ln level. Due to the lack of fiber in the retroperitoneal space and weak connection with other organs, the duodenum of a newborn is characterized by significant mobility. The glands of the mucous membrane are better developed than in the rest of the intestine. The duodenum contains the duodenal glands. In mature newborns, the duodenal glands are highly branched and reach their maximum development. In the area of confluence of the bile duct there is a rhythm sensor of the duodenum and small intestine. The small intestine of the newborn plays a leading role in digestion. Its absorption capacity is increased by circular folds of the mucous membrane, which are well expressed and are located mainly in the initial section. The mucous membrane is covered with villi, the total number of which is almost the same as in adults. Between the villi, in the intestinal crypts, which are 2 times deeper in newborns, there are intestinal glands that produce juice. At the bottom of the crypts, in greater numbers than in adults, there are enterocytes with acidophilic granules (Paneth cells) that secrete digestive enzymes. In a newborn, they are also found on the surface of the villi. The muscular membrane of the small intestine is underdeveloped and its longitudinal layer is especially thin. The elastic apparatus is poorly developed.

The large intestine in the first weeks of life is variable in shape, size and position. All parts of the large intestine are sufficiently expressed at the time of birth. The most developed section is the sigmoid colon, which is characterized by great length, tortuosity and pronounced mobility. The appendix is sometimes a direct continuation of the cecum, since it has a fairly wide entrance. The latter contributes to a good evacuation of its contents and explains the rarity of acute appendicitis in newborns.

The digestion process in the neonatal period has its own characteristics, due to the nature of the food and the degree of maturity of the enzyme systems. It is known that food digestion occurs as a result of cavity and parietal cleavage. In newborns and children who are breastfed, cavity digestion is almost not developed, because milk does not need this method of digestion. With the transition to mixed and artificial feeding, the proportion of cavity digestion increases.

Low activity of enzyme systems, and sometimes a complete absence of enzymes due to the immaturity of the child is the cause of various digestive disorders.

In the first 48-72 hours after birth, meconium is excreted, then "transitional stool", which is replaced by regular stool in 5-7 days. The number of bowel movements is determined by the composition of the food and the individual characteristics of the child. In the first 1-2 weeks, the stool is up to 5-6 times, then it gradually decreases to 2-4 times a day.

In a newborn, before the first feeding, the digestive tract is sterile. From the 2-3rd day, the distal parts of the intestine begin to be populated by various microflora - streptococci, enterococci, Escherichia coli, Proteus. With the appearance of "transitional" and then normal stool, it begins to prevail when breastfeeding Bacillus bifidus, and when feeding with cow's milk - Escherichia coli. The "transformation phase" of the intestinal flora begins. The spread of microorganisms to the upper intestine is a pathological process. In the duodenum and jejunum, bacteria, as a rule, are few. The symbiotic flora of the gastrointestinal tract produces B vitamins, promotes the synthesis of vitamin K and is one of the factors in the nonspecific defense of the newborn's body against pathogens.

The digestive organs include the mouth, esophagus, stomach, and intestines. The pancreas and liver are involved in digestion. The digestive organs are laid in the first 4 weeks of the prenatal period, by 8 weeks of pregnancy, all parts of the digestive system are determined. The fetus begins to swallow the amniotic fluid by 16–20 weeks of gestation. Digestive processes occur in the intestines of the fetus, where an accumulation of original feces - meconium is formed.

FEATURES OF THE ORAL CAVITY

The main function of the baby's oral cavity after birth is to provide the sucking act. These features are: small size of the oral cavity, large tongue, well-developed musculature of the lips and chewing muscles, transverse folds on the mucous membrane of the lips, roller-like thickening of the gums, there are lumps of fat (Bisha's lumps) in the cheeks, which give elasticity to the cheeks.

The salivary glands in children are not sufficiently developed after birth; little saliva is released in the first 3 months. The development of the salivary glands is completed by 3 months of age.

FEATURES OF THE OESOPHAGUS

The esophagus in young children has a fusiform shape, it is narrow and short. In a newborn, its length is only 10 cm, in children at 1 year of age - 12 cm, at 10 years old - 18 cm. Its width is, respectively, at 7 years old - 8 mm, at 12 years old - 15 mm.

There are no glands on the mucous membrane of the esophagus. It has thin walls, poor development of muscle and elastic tissues, and is well supplied with blood. The entrance to the esophagus is high. He has no physiological constrictions.

FEATURES OF THE STOMACH

In infancy, the stomach is horizontal. As the child grows and develops, during the period when the child begins to walk, the stomach gradually takes an upright position, and by the age of 7-10 it is located in the same way as in adults. The capacity of the stomach is gradually increasing: at birth it is 7 ml, at 10 days - 80 ml, a year - 250 ml, at 3 years old - 400-500 ml, at 10 years old - 1500 ml.

V = 30 ml + 30? n,

where n is the age in months.

The peculiarity of the stomach in children is the weak development of its fundus and the cardiac sphincter against the background of good development of the pyloric region. This contributes to frequent regurgitation in the baby, especially if air enters the stomach during sucking.

The mucous membrane of the stomach is relatively thick; against this background, there is a weak development of the gastric glands. As the child grows, the active glands of the gastric mucosa are formed and enlarged 25 times, as in an adult state. In connection with these features, the secretory apparatus in children of the first year of life is insufficiently developed. The composition of gastric juice in children is similar to that of adults, but its acidic and enzymatic activity is much lower. Barrier activity of gastric juice is low.

The main active enzyme of gastric juice is rennet (labenzyme), which provides the first phase of digestion - milk curdling.

Very little lipase is secreted in the stomach of an infant. This deficiency is compensated for by the presence of lipase in breast milk, as well as in the baby's pancreatic juice. If a baby receives cow's milk, the fats in the stomach are not broken down.

Absorption in the stomach is insignificant and concerns substances such as salts, water, glucose, and protein breakdown products are only partially absorbed. The timing of evacuation of food from the stomach depends on the type of feeding. Human milk is retained in the stomach for 2-3 hours.

FEATURES OF THE PANCREAS

The pancreas is small. In a newborn, its length is 5–6 cm, and by 10 years of age, it triples. The pancreas is located deep in the abdominal cavity at the level of the X thoracic vertebra; at an older age, it is located at the level of the I lumbar vertebra. Its intensive growth occurs until the age of 14.

The size of the pancreas in children in the first year of life (cm):

1) newborn - 6.0? 1.3? 0.5;

2) 5 months - 7.0? 1.5? 0.8;

3) 1 year - 9.5? 2.0? 1.0.

The pancreas is richly supplied with blood vessels. Its capsule is less dense than in adults, and consists of fine-fibrous structures. Its excretory ducts are wide, which ensures good drainage.

The child's pancreas has exocrine and intrasecretory functions. It produces pancreatic juice, which is composed of albumin, globulins, trace elements and electrolytes, enzymes necessary for the digestion of food. The enzymes include proteolytic enzymes: trypsin, chymotrypsin, elastase, as well as lipolytic enzymes and amylolytic enzymes. The regulation of the pancreas is provided by secretin, which stimulates the separation of the liquid part of pancreatic juice, and pancreosimin, which enhances the secretion of enzymes along with other hormone-like substances that are produced by the mucous membrane of the duodenum and small intestine.

The intrasecretory function of the pancreas is performed due to the synthesis of hormones responsible for the regulation of carbohydrate and fat metabolism.

LIVER

The liver of a newborn is the largest organ, occupying 1/3 of the volume of the abdominal cavity. At 11 months, its mass doubles, by 2-3 years it triples, by 8 years it increases 5 times, by 16-17 years the mass of the liver - 10 times.

The liver performs the following functions:

1) produces bile, which is involved in intestinal digestion;

2) stimulates intestinal motility due to the action of bile;

3) deposits nutrients;

4) carries out a barrier function;

5) participates in the metabolism, including the transformation of vitamins A, D, C, B 12, K;

6) in the prenatal period is a hematopoietic organ.

After birth, further formation of liver lobules occurs. The functional capabilities of the liver in young children are low: in newborns, the metabolism of indirect bilirubin is not fully carried out.

FEATURES OF THE GALL BLADDER

With age, the size of the gallbladder increases, bile of a different composition begins to be secreted than in young children. The length of the common bile duct increases with age.

The size of the gallbladder in children (Chapova O.I., 2005):

1) newborn - 3.5? 1.0? 0.68 cm;

2) 1 year - 5.0? 1.6? 1.0 cm;

3) 5 years - 7.0? 1.8? 1.2 cm;

4) 12 years old - 7.7? 3.7? 1.5 cm.

FEATURES OF THE SMALL INTESTINE

The intestines of children are relatively longer than those of adults.

The ratio of the length of the small intestine to body length in a newborn is 8.3: 1, in the first year of life - 7.6: 1, at 16 years old - 6.6: 1.

The length of the small intestine in a child of the first year of life is 1.2–2.8 m. The area of the inner surface of the small intestine in the first week of life is 85 cm 2, in an adult - 3.3? 103 cm 2. The area of the small intestine increases due to the development of epithelium and microvilli.

The small intestine is anatomically divided into 3 sections. The first section is the duodenum, the length of which in a newborn is 10 cm, in an adult it reaches 30 cm. It has three sphincters, the main function of which is to create an area of low pressure, where food contacts with pancreatic enzymes.

The second and third sections are represented by the small and ileum. The length of the small intestine is 2/5 of the length up to the ileocecal angle, the remaining 3/5 is the ileum.

Digestion of food, absorption of its ingredients occurs in the small intestine. The intestinal mucosa is rich in blood vessels, the epithelium of the small intestine is rapidly renewed. Intestinal glands in children are larger, lymphoid tissue is scattered throughout the intestines. As the child grows, Peyer's patches form.

FEATURES OF THE LARGE INTESTINAL

The large intestine is divided into different sections and develops after birth. In children under 4 years of age, the ascending intestine is longer in length than the descending one. The sigmoid colon is relatively long. Gradually, these features disappear. The cecum and appendix are mobile, and the appendix is often atypical.

The rectum in children in the first months of life is relatively long. In newborns, the rectal ampulla is undeveloped, the surrounding fatty tissue is poorly developed. By the age of 2, the rectum takes its final position, which contributes to prolapse of the rectum in early childhood with straining, with persistent constipation and tenesmus in weakened children.

The epiploon in children under 5 years of age is short.

Juice production in children in the large intestine is small, but increases sharply with mechanical irritation.

In the large intestine, water is absorbed and feces are formed.

FEATURES OF THE INTESTINAL MICROFLORA

The fetal gastrointestinal tract is sterile. When a child comes into contact with the environment, it is colonized by microflora. Microflora in the stomach and duodenum is scarce. In the small and large intestines, the number of microbes increases and depends on the type of feeding. The main microflora is B. bifidum, the growth of which is stimulated by β-lactose in breast milk. With artificial feeding, the conditionally pathogenic gram-negative Escherichia coli dominates in the intestine. Normal intestinal flora has two main functions:

1) creation of an immunological barrier;

2) synthesis of vitamins and enzymes.

DIGESTIVE FEATURES IN YOUNG CHILDREN

The digestion of fat depends on the type of feeding. Cow's milk fats contain long-chain fats that are degraded by pancreatic lipase in the presence of fatty acids.

Fat absorption occurs in the end and middle sections of the small intestine. The breakdown of milk sugar in children occurs in the border of the intestinal epithelium. Human milk contains? -Lactose, cow's milk contains? -Lactose. In this regard, with artificial feeding, the carbohydrate composition of food is changed. Vitamins are also absorbed in the small intestine.

In the extrauterine period, the gastrointestinal tract is the only source of nutrients and water needed both to maintain life and for the growth and development of the fetus.

Features of the digestive system in children

Anatomical and physiological features of the digestive system

Young children (especially newborns) have a number of morphological features common to all parts of the gastrointestinal tract:

thin, delicate, dry, easily injured mucous membrane;
richly vascularized submucosal layer, consisting mainly of loose fiber;
insufficiently developed elastic and muscle tissue;
low secretory function of glandular tissue, which separates a small amount of digestive juices with a low content of enzymes.

These features of the digestive system make it difficult to digest food, if the latter does not correspond to the age of the child, reduce the barrier function of the gastrointestinal tract and lead to frequent diseases, create the prerequisites for a general systemic response to any pathological effect and require very careful and thorough care of the mucous membranes.

Oral cavity in a child

In a newborn and a child in the first months of life, the oral cavity has a number of features that ensure the act of sucking. These include: a relatively small volume of the oral cavity and a large tongue, good development of the muscles of the mouth and cheeks, roller-like duplicates of the mucous membrane of the gums and transverse folds on the mucous membrane of the lips, fatty bodies (Bisha's lumps) in the thickness of the cheeks, characterized by significant elasticity due to the predominance they contain solid fatty acids. The salivary glands are underdeveloped. However, insufficient salivation is mainly due to the immaturity of the nerve centers that regulate it. As they mature, the amount of saliva increases, and therefore, at 3-4 months of age, the child often develops the so-called physiological salivation due to the not yet developed automatism of swallowing it.

In newborns and infants, the oral cavity is relatively small. The lips of newborns are thick, there are transverse ridges on their inner surface. The orbicularis muscle of the mouth is well developed. The cheeks in newborns and young children are rounded and convex due to the presence of a rounded fatty body (Bisha's fatty lumps) between the skin and the well-developed buccal muscle, which subsequently, starting from the age of 4, gradually atrophies.

The hard palate is flat, its mucous membrane forms poorly expressed transverse folds, poor in glands. The soft palate is relatively short, almost horizontal. The palatine curtain does not touch the back of the pharynx, which allows the baby to breathe while sucking. With the appearance of milk teeth, a significant increase in the size of the alveolar processes of the jaws occurs, and the roof of the hard palate rises, as it were. The tongue in newborns is short, wide, thick and inactive; well-defined papillae are visible on the mucous membrane. The tongue occupies the entire oral cavity: when the mouth is closed, it comes into contact with the cheeks and the hard palate, protrudes forward between the jaws in the vestibule of the mouth.

Oral mucosa

The mucous membrane of the oral cavity in children, especially young children, is thin and easily vulnerable, which must be taken into account when treating the oral cavity. The mucous membrane of the floor of the oral cavity forms a noticeable fold, covered with a large number of villi. A bulging in the form of a roller is also present on the mucous membrane of the cheeks in the gap between the upper and lower jaws.In addition, there are transverse folds (rollers) on the hard palate, roller-like thickenings on the gums. All these formations ensure the sealing of the oral cavity during the sucking process. On the mucous membrane in the area of the hard palate in the midline in newborns, Bon's nodules are located - yellowish formations - retention cysts of the salivary glands, disappearing by the end of the first month of life.

The mucous membrane of the oral cavity in children in the first 3-4 months of life is relatively dry, which is due to insufficient development of the salivary glands and saliva deficiency. The salivary glands (parotid, submandibular, sublingual, small glands of the oral mucosa) in a newborn are characterized by low secretory activity and secrete a very small amount of thick, viscous saliva, which is necessary for gluing the lips and sealing the oral cavity during sucking. The functional activity of the salivary glands begins to increase at the age of 1.52 months; in 34-month-old children, saliva often flows out of the mouth due to the immaturity of the regulation of salivation and swallowing of saliva (physiological salivation). The most intense growth and development of the salivary glands occurs between the ages of 4 months and 2 years. By the age of 7, a child produces the same amount of saliva as an adult. The reaction of saliva in newborns is often neutral or slightly acidic. From the first days of life, saliva contains osamylase and other enzymes necessary for the breakdown of starch and glycogen. In newborns, the concentration of amylase in saliva is low; during the first year of life, its content and activity increase significantly, reaching a maximum level at 2-7 years.

Pharynx and larynx in a child

The pharynx of a newborn has the shape of a funnel, its lower edge is projected at the level of the intervertebral disc between C And | and C 1 V. By adolescence, he falls to the level C vl -C VII. The larynx in infants is also funnel-shaped and located differently than in adults. The entrance to the larynx is located high above the lower posterior edge of the palatine curtain and is connected to the oral cavity. Food moves to the sides of the protruding larynx, so the baby can breathe and swallow at the same time without interrupting sucking.

Sucking and swallowing in a baby

Sucking and swallowing are congenital unconditioned reflexes. In healthy and mature newborns, they are already formed by the time of birth. When sucking, the baby's lips tightly grip the nipple of the breast. The jaws squeeze it, and the communication between the oral cavity and the outside air stops. Negative pressure is created in the child's oral cavity, which is facilitated by the lowering of the lower jaw along with the tongue down and back. Then breast milk enters the rarefied space of the mouth. All elements of the newborn's chewing apparatus are adapted for the breast-sucking process: the gingival membrane, pronounced palatine transverse folds and fatty bodies in the cheeks. The physiological infant retrognathia, which later turns into orthognathia, also serves as an adaptation of the newborn's oral cavity to sucking. In the process of sucking, the baby makes rhythmic movements with the lower jaw from front to back. The absence of the articular tubercle facilitates the sagittal movements of the child's lower jaw.

Child's esophagus

The esophagus is a fusiform muscle tube lined with a mucous membrane from the inside. By birth, the esophagus is formed, its length in a newborn is 10-12 cm, at the age of 5 years - 16 cm, and at 15 years old - 19 cm.The ratio between the length of the esophagus and the length of the body remains relatively constant and is approximately 1: 5. The width of the esophagus in a newborn is 5-8 mm, at 1 year old - 10-12 mm, by 3-6 years - 13-15 mm and by 15 years - 18-19 mm. The size of the esophagus must be taken into account when fibro-eso-phago-gastroduodenoscopy (FEGDS), duodenal intubation and gastric lavage.

Anatomical narrowing of the esophagus in newborns and children of the first year of life is poorly expressed and forms with age. The wall of the esophagus in a newborn is thin, the muscular membrane is poorly developed, it grows intensively up to 12-15 years. The mucous membrane of the esophagus in infants is poor in glands. Longitudinal folds appear at the age of 2-2.5 years. The submucosa is well developed, rich in blood vessels.

Outside the act of swallowing, the passage of the pharynx into the esophagus is closed. Peristalsis of the esophagus occurs during swallowing movements.

The gastrointestinal tract and the size of the esophagus in children, depending on age.

During anesthesia and the process of intensive care, stomach sounding is often performed, so the anesthesiologist must know the age of the esophagus (table).

Table. The size of the esophagus in children, depending on age

In young children, there is a physiological weakness of the cardiac sphincter and, at the same time, good development of the muscular layer of the pylorus. All this predisposes to regurgitation and vomiting. This must be remembered when carrying out anesthesia, especially with the use of muscle relaxants, since in these cases regurgitation is possible - passive (and therefore late noticed) leakage of stomach contents, which can lead to its aspiration and the development of severe aspiration pneumonia.

Stomach capacity increases in proportion to age up to 1-2 years. Further increase is associated not only with the growth of the body, but also with the characteristics of nutrition. The approximate values of the stomach capacity in newborns and infants are presented in the table.

Table. Stomach capacity in young children

What is the size of the esophagus in children?

The indicated values are very approximate, especially in pathological conditions. For example, with obstruction of the upper gastrointestinal tract, the walls of the stomach can stretch, which leads to an increase in its capacity by 2-5 times.

The physiology of gastric secretion in children of different ages, in principle, does not differ from that in adults. The acidity of gastric juice may be slightly lower than in adults, but this often depends on the nature of the diet. The pH of gastric juice in infants is 3.8-5.8, in adults, in the midst of digestion, up to 1.5-2.0.

Stomach motility under normal conditions depends on the nature of the diet, as well as on neuroreflex impulses. High activity of the vagus nerve stimulates gastrospasm, and the splanchnic nerve stimulates the pyloric spasm.

The transit time of food (chyme) through the intestines in newborns is 4-18 hours, in older children - up to a day. Of this time, 7-8 hours are spent on passing through the small intestine and 2-14 hours on the large intestine. With artificial feeding of infants, the digestion time can be up to 48 hours.

Child's stomach

Features of the child's stomach

The stomach of a newborn has the shape of a cylinder, bovine horn or a fish hook and is located high (the inlet of the stomach is at level T VIII -T IX, and the gatekeeper's opening is at the level of T x1 -T x | 1). As the child grows and develops, the stomach sinks, and by the age of 7 years its inlet (with an upright body position) is projected between TX | and T X || , and the output is between T x || and L ,. In infants, the stomach is horizontal, but as soon as the child begins to walk, he gradually takes a more upright position.

The cardial part, the fundus and the pyloric part of the stomach in the newborn are poorly expressed, the pylorus is wide. The entrance part of the stomach is often located above the diaphragm, the angle between the abdominal part of the esophagus and the adjacent wall of the fundus of the stomach is insufficiently expressed, the muscular membrane of the cardiac part of the stomach is also poorly developed. The Gubarev valve (a fold of the mucous membrane that protrudes into the esophageal cavity and prevents the return of food) is almost not pronounced (it develops by 8-9 months of life), the cardiac sphincter is functionally defective, while the pyloric stomach is functionally well developed at birth.

These features determine the possibility of throwing the contents of the stomach into the esophagus and the development of peptic lesions of its mucous membrane. In addition, the tendency of children in the first year of life to regurgitate and vomit is associated with the lack of a tight grip of the esophagus with the legs of the diaphragm, as well as a violation of innervation with increased intragastric pressure. Regurgitation is also facilitated by swallowing air when sucking (aerophagia) with improper feeding technique, short frenulum of the tongue, greedy sucking, too rapid release of milk from the mother's breast.

In the first weeks of life, the stomach is located in an oblique frontal plane, in front it is completely covered by the left lobe of the liver, and therefore the fundus of the stomach in the supine position is located below the antral pyloric region, therefore, to prevent aspiration after feeding, children should be given an elevated position. By the end of the first year of life, the stomach lengthens, and in the period from 7 to 11 years it takes a shape similar to that of an adult. By the age of 8, the formation of its cardiac part is completed.

The anatomical capacity of a newborn's stomach is 30-35 cm 3, by the 14th day of life, it increases to 90 cm 3. Physiological capacity is less than anatomical, and on the first day of life is only 7-10 ml; By the 4th day after the start of enteral nutrition, it increases to 40-50 ml, and by the 10th day - up to 80 ml. Subsequently, the capacity of the stomach increases monthly by 25 ml and by the end of the first year of life it is 250-300 ml, and by 3 years - 400-600 ml. An intensive increase in the capacity of the stomach begins after 7 years and by 10-12 years is 1300-1500 ml.

The muscular membrane of the stomach in a newborn is poorly developed, it reaches its maximum thickness only by 15-20 years. The mucous membrane of the stomach of the newborn is thick, the folds are high. During the first 3 months of life, the surface of the mucous membrane increases by 3 times, which contributes to better digestion of milk. By the age of 15, the surface of the gastric mucosa increases 10 times. With age, the number of gastric pits increases, into which the openings of the gastric glands open. The stomach glands at birth are morphologically and functionally underdeveloped, their relative number (per 1 kg of body weight) in newborns is 2.5 times less than in adults, but increases rapidly with the onset of enteral nutrition.

The secretory apparatus of the stomach in children of the first year of life is insufficiently developed, its functional abilities are low. The gastric juice of an infant contains the same components as the gastric juice of an adult: hydrochloric acid, chymosin (curdles milk), pepsins (breaks down proteins into albumoses and peptones) and lipase (breaks down neutral fats into fatty acids and glycerin).

Children in the first weeks of life are characterized by a very low concentration of hydrochloric acid in gastric juice and its low total acidity. It increases significantly after the introduction of complementary foods, i.e. when switching from lactotrophic nutrition to normal. In parallel with a decrease in the pH of gastric juice, the activity of carbonic anhydrase, which is involved in the formation of hydrogen ions, increases. In children of the first 2 months of life, the pH value is mainly determined by the hydrogen ions of lactic acid, and subsequently by hydrochloric acid.

The synthesis of proteolytic enzymes by the main cells begins in the antenatal period, but their content and functional activity in newborns is low and gradually increases with age. The leading role in the hydrolysis of proteins in newborns is played by fetal pepsin, which has a higher proteolytic activity. In infants, there were significant fluctuations in the activity of proteolytic enzymes, depending on the nature of feeding (with artificial feeding, the activity indicators are higher). In children of the first year of life (in contrast to adults), a high activity of gastric lipase is noted, which provides hydrolysis of fats in the absence of bile acids in a neutral environment.

Low concentrations of hydrochloric acid and pepsins in the stomach in newborns and infants determine a reduced protective function of gastric juice, but at the same time contribute to the preservation of Ig that come with mother's milk.

In the first months of life, the motor function of the stomach is reduced, the peristalsis is sluggish, the gas bubble is enlarged. The frequency of peristaltic contractions in newborns is the lowest, then it actively increases and after 3 years it stabilizes. By the age of 2, the structural and physiological characteristics of the stomach correspond to those of an adult. In infants, it is possible to increase the tone of the stomach muscles in the pyloric region, the maximum manifestation of which is pylorospasm. At an older age, cardiospasm is sometimes observed. The frequency of peristaltic contractions in newborns is the lowest, then it actively increases and after 3 years it stabilizes.

In infants, the stomach is located horizontally, with the pyloric part located near the midline, and the lesser curvature facing posteriorly. As the baby begins to walk, the axis of the stomach becomes more vertical. By the age of 7-11, it is located in the same way as in adults. The capacity of the stomach in newborns is 30 - 35 ml, by 1 year it increases to 250 - 300 ml, by the age of 8 it reaches 1000 ml. The cardiac sphincter in infants is very poorly developed, and the pyloric sphincter functions satisfactorily. This contributes to the regurgitation often seen at this age, especially when the stomach is distended by swallowing air during sucking ("physiological aerophagia"). There are fewer glands in the stomach lining of young children than in adults. And although some of them begin to function even in utero, in general, the secretory apparatus of the stomach in children of the first year of life is insufficiently developed and its functional abilities are low. The composition of gastric juice in children is the same as in adults (hydrochloric acid, lactic acid, pepsin, rennet, lipase, sodium chloride), but acidity and enzyme activity are much lower, which not only affects digestion, but also determines a low barrier stomach function. This makes it absolutely necessary to carefully observe the sanitary and hygienic regime during feeding of children (breast toilet, clean hands, correct expression of milk, sterility of nipples and bottles). In recent years, it has been established that the bactericidal properties of gastric juice are provided by lysozyme produced by the cells of the surface epithelium of the stomach.

The maturation of the secretory apparatus of the stomach occurs earlier and more intensively in children who are bottle-fed, which is associated with the adaptation of the body to more difficult to digest food. The functional state and enzymatic activity depend on many factors: the composition of the ingredients and their quantity, the emotional tone of the child, his physical activity, and general condition. It is well known that fats suppress gastric secretion, proteins stimulate it. Depressed mood, fever, intoxication are accompanied by a sharp decrease in appetite, i.e., a decrease in gastric acid secretion. Absorption in the stomach is insignificant and mainly concerns substances such as salts, water, glucose, and only partially - protein breakdown products. Stomach motility in children during the first months of life is slowed down, peristalsis is sluggish, and the gas bubble is enlarged. The timing of evacuation of food from the stomach depends on the nature of feeding. So, human milk is retained in the stomach for 2-3 hours, cow's milk - for a longer time (3-4 hours and even up to 5 hours, depending on the buffering properties of milk), which indicates the difficulties of digesting the latter and the need to switch to more rare feedings.

Child's intestines

The intestine starts from the pylorus of the stomach and ends with the anus. Distinguish between small and large intestines. The small intestine is subdivided into the duodenum, the jejunum, and the ileum; colon - into the blind, colon (ascending, transverse, descending, sigmoid) and rectum. The relative length of the small intestine in a newborn is large: there is 1 m per 1 kg of body weight, and only 10 cm in adults.

In children, the intestine is relatively longer than in adults (in an infant it exceeds the body length by 6 times, in adults - by 4 times), but its absolute length individually varies within wide limits. The cecum and appendix are mobile, the latter is often located atypically, thereby complicating the diagnosis of inflammation. The sigmoid colon is relatively longer than in adults, and even forms loops in some children, which contributes to the development of primary constipation. With age, these anatomical features disappear. In connection with the weak fixation of the mucous and submucous membranes of the rectum, it may prolapse with persistent constipation and tenesmus in weakened children. The mesentery is longer and easily stretchable, and therefore easily torsion, intussusception, etc. The omentum in children under 5 years of age is short, therefore, the possibility of localization of peritonitis in a limited area of the abdominal cavity is almost excluded. Of the histological features, it should be noted the good expression of the villi and the abundance of small lymphatic follicles.

All intestinal functions (digestive, absorption, barrier and motor) in children differ from those of adults. The digestion process, which begins in the mouth and stomach, continues in the small intestine under the influence of pancreatic juice and bile secreted into the duodenum, as well as intestinal juice. By the time the child is born, the secretory apparatus is generally formed, and even in the smallest children, the same enzymes are determined in the intestinal juice as in adults (enterokinase, alkaline phosphatase, erepsin, lipase, amylase, maltase, lactase, nuclease), but significantly less active. Only mucus is secreted in the large intestine. Under the influence of intestinal enzymes, mainly of the pancreas, the breakdown of proteins, fats and carbohydrates occurs. The process of digestion of fats is especially intense due to the low activity of lipolytic enzymes.

In breastfed babies, bile-emulsified lipids are broken down by 50% under the influence of breast milk lipase. Digestion of carbohydrates occurs in the small intestine parietally under the influence of pancreatic juice amylase and 6 disaccharidases localized in the brush border of enterocytes. In healthy children, only a small part of the sugars does not undergo enzymatic breakdown and is converted into lactic acid in the large intestine by bacterial decomposition (fermentation). Putrefaction processes do not occur in the intestines of healthy infants. The products of hydrolysis, formed as a result of cavity and parietal digestion, are absorbed mainly in the small intestine: glucose and amino acids into the blood, glycerol and fatty acids into the lymph. In this case, both passive mechanisms (diffusion, osmosis) and active transport with the help of carrier substances play a role.

The structural features of the intestinal wall and its large area determine in young children a higher absorption capacity than in adults, and at the same time an insufficient barrier function due to the high permeability of the mucous membrane for toxins, microbes and other pathogenic factors. The components of human milk are most easily absorbed, the protein and fats of which in newborns are partially absorbed unbroken.

The motor (motor) function of the intestine is carried out in children very vigorously due to pendulum-like movements, stirring food, and peristaltic, moving food to the exit. Active motor skills are reflected in the frequency of bowel movements. In infants, defecation occurs reflexively, in the first 2 weeks of life up to 3 - 6 times a day, then less often, by the end of the first year of life, it becomes an arbitrary act. In the first 2 to 3 days after birth, the child secretes meconium (original feces) of a greenish-black color. It consists of bile, epithelial cells, mucus, enzymes, and swallowed amniotic fluid. The feces of healthy newborns who are breastfed have a mushy consistency, golden yellow color, and a sour odor. In older children, the chair is decorated, 1-2 times a day.

Child's duodenum

The duodenum of a newborn has a ring-shaped shape (bends are formed later), its beginning and end are located at the level L. In children older than 5 months, the upper part of the duodenum is at the level TX | 1; the descending part gradually descends by the age of 12 to the level of L IM L IV. In young children, the duodenum is very mobile, but by the age of 7, adipose tissue appears around it, which fixes the intestine, reducing its mobility.

In the upper part of the duodenum, acidic gastric chyme is alkalized, prepared for the action of enzymes that come from the pancreas and are formed in the intestines, and mixed with bile. The folds of the duodenal mucosa in newborns are lower than in older children, the duodenal glands are small in size, and weaker branched out than in adults. The duodenum has a regulatory effect on the entire digestive system through hormones secreted by the endocrine cells of its mucous membrane.

Small intestine of a child

The jejunum occupies approximately 2/5, and the ileum 3/5 of the length of the small intestine (without the duodenum). The ileum ends with an ileocecal valve (Bauhinia valve). In young children, a relative weakness of the ileocecal valve is noted, and therefore the contents of the cecum, the richest in bacterial flora, can be thrown into the ileum, causing a high frequency of inflammatory lesions of its terminal section.

The small intestine in children occupies an unstable position, depending on the degree of its filling, body position, tone of the intestines and muscles of the anterior abdominal wall. Compared to adults, the intestinal loops are more compact (due to the relatively large size of the liver and the underdevelopment of the small pelvis). After 1 year of life, as the small pelvis develops, the location of the loops of the small intestine becomes more constant.

The small intestine of an infant contains a relatively large amount of gas, the volume of which gradually decreases until it disappears completely by the age of 7 (adults normally have no gas in the small intestine).

The mucous membrane is thin, richly vascularized and has increased permeability, especially in children of the first year of life. The intestinal glands in children are larger than in adults. Their number increases significantly during the first year of life. In general, the histological structure of the mucous membrane becomes similar to that in adults by the age of 5-7 years. In newborns, single and group lymphoid follicles are present in the thickness of the mucous membrane. Initially, they are scattered throughout the intestine, and later they are grouped mainly in the ileum in the form of group lymphatic follicles (Peyer's patches). Lymphatic vessels are numerous and have a wider lumen than in adults. The lymph flowing from the small intestine does not pass through the liver, and the products of absorption go directly into the blood.

The muscular layer, especially its longitudinal layer, is poorly developed in newborns. The mesentery in newborns and young children is short, increases significantly in length during the first year of life.

In the small intestine, the main stages of the complex process of cleavage and absorption of nutrients take place with the combined action of intestinal juice, bile and pancreatic secretions. The breakdown of nutrients with the help of enzymes occurs both in the cavity of the small intestine (cavity digestion) and directly on the surface of its mucous membrane (parietal, or membrane, digestion, which dominates in infancy during the period of milk feeding).

The secretory apparatus of the small intestine is generally formed at birth. Even in newborns, the same enzymes can be detected in intestinal juice as in adults (enterokinase, alkaline phosphatase, lipase, amylase, maltase, nuclease), but their activity is lower and increases with age. The peculiarities of protein assimilation in young children include the high development of pinocytosis by epithelial cells of the intestinal mucosa, as a result of which milk proteins in children in the first weeks of life can pass into the blood in an unchanged form, which can lead to the appearance of AT to cow's milk proteins. In children over one year old, proteins undergo hydrolysis to form amino acids.

Already from the first days of a child's life, all parts of the small intestine have a fairly high hydrolytic activity. Disaccharidases in the intestine appear in the prenatal period. Maltase activity is high enough at birth and remains so in adults; a little later, sucrase activity increases. In the first year of life, a direct correlation is observed between the age of the child and the activity of maltase and sucrase. Lactase activity increases rapidly in the last weeks of gestation, and after birth, the increase in activity decreases. It remains high throughout the period of breastfeeding, by the age of 4-5 years there is a significant decrease in it, it is the smallest in adults. It should be noted that human milk rlactose is absorbed more slowly than cow's milk oslactose, and partially enters the large intestine, which contributes to the formation of gram-positive intestinal microflora in breastfed children.

Due to the low activity of lipase, the process of digestion of fats is especially intense.

Fermentation in the intestines of infants complements the enzymatic breakdown of food. There is no rotting in the intestines of healthy children during the first months of life.

Absorption is closely related to parietal digestion and depends on the structure and function of cells in the surface layer of the mucous membrane of the small intestine.

Large intestine of a child

The large intestine in a newborn has an average length of 63 cm. By the end of the first year of life, it lengthens to 83 cm, and subsequently its length is approximately equal to the height of the child. By birth, the colon does not complete its development. The newborn does not have omental processes (appear in the 2nd year of the child's life), the ribbons of the colon are barely outlined, the haustra of the colon are absent (appear after 6 months). Colon ribbons, haustra and omental processes are finally formed by 6-7 years.

The cecum in newborns has a conical or funnel-shaped shape, its width prevails over its length. It is located high (in a newborn directly under the liver) and descends into the right iliac fossa by mid-adolescence. The higher the cecum is, the more underdeveloped the ascending colon. The ileocecal valve in newborns looks like small folds. The ileocecal foramen is annular or triangular, gaping. In children over one year old, it becomes slit-like. The appendix in a newborn has a conical shape, the entrance to it is wide open (the valve is formed in the first year of life). The appendix has great mobility due to the long mesentery and can be placed in any part of the abdominal cavity, including retrocecal. After birth, lymphoid follicles appear in the appendix, which receive their maximum development by 10-14 years.

The colon surrounds the loops of the small intestine. The ascending part of the newborn is very short (2-9 cm) and increases after the colon takes its final position. The transverse part of the colon in a newborn usually has an oblique position (its left bend is located above the right) and only by 2 years it takes a horizontal position. The mesentery of the transverse part of the colon in a newborn is short (up to 2 cm), within 1.5 years its width increases to 5-8.5 cm, due to which the intestine acquires the ability to easily move when filling the stomach and small intestine. The descending part of the colon in a newborn has a smaller diameter than other parts of the colon. She is poorly mobile and rarely has a mesentery.

The sigmoid colon in a newborn is relatively long (12-29 cm) and mobile. Up to 5 years old, it is located high in the abdominal cavity due to the underdevelopment of the small pelvis, and then descends into it. Its mobility is due to the long mesentery. By the age of 7, the intestine loses its mobility as a result of shortening of the mesentery and the accumulation of adipose tissue around it. The large intestine provides water resorption and evacuation-reservoir function. In it, the absorption of digested food is completed, the remaining substances are split (both under the influence of enzymes coming from the small intestine and bacteria inhabiting the large intestine), and the formation of feces occurs.

The mucous membrane of the large intestine in children is characterized by a number of features: crypts are deepened, the epithelium is flatter, and the rate of its proliferation is higher. Colon secretion is insignificant under normal conditions; however, it sharply increases with mechanical irritation of the mucous membrane.

Child's rectum

The rectum of a newborn has a cylindrical shape, does not have an ampoule (its formation occurs in the first period of childhood) and bends (formed simultaneously with the sacral and coccygeal bends of the spine), its folds are not pronounced. In children of the first months of life, the rectum is relatively long and poorly fixed, since the fatty tissue is not developed. The rectum takes its final position by 2 years. In a newborn, the muscular membrane is poorly developed. Due to the well-developed submucosa and poor fixation of the mucous membrane relative to the submucosa, as well as insufficient development of the sphincter of the anus in young children, its prolapse often occurs. The anal opening in children is located dorsally in comparison with adults, at a distance of 20 mm from the coccyx.

Functional features of the child's intestines

The motor function of the intestine (motility) consists of pendulum movements that occur in the small intestine, due to which its contents are mixed, and peristaltic movements that propel the chyme towards the large intestine. The colon is also characterized by antiperistaltic movements that thicken and form feces.

Motor skills in young children are more active, which contributes to frequent bowel movements. In infants, the duration of the passage of food gruel through the intestines is from 4 to 18 hours, and in older children - about a day. High motor activity of the intestine in combination with insufficient fixation of its loops determines the tendency to intussusception.

Defecation in children

During the first hours of life, there is a discharge of meconium (original feces) - a sticky mass of dark green color with a pH of about 6.0. Meconium consists of desquamated epithelium, mucus, remnants of amniotic fluid, bile pigments, etc. On the 2-3rd day of life, feces are mixed with meconium, and from the 5th day the feces take on a form characteristic of a newborn. In children of the first month of life, bowel movements usually occur after each feeding - 5-7 times a day, in children from the 2nd month of life - 3-6 times, in 1 year - 12 times. With mixed and artificial feeding, bowel movements are more rare.

Feces in breastfed babies are mushy, yellow, acidic and have a sour odor; with artificial feeding, feces have a thicker consistency (putty), lighter, sometimes with a grayish tinge, neutral or even alkaline reaction, a sharper odor. The golden yellow color of feces in the first months of a child's life is due to the presence of bilirubin, greenish - biliverdin.

In infants, defecation occurs reflexively, without the participation of the will. From the end of the first year of life, a healthy child gradually becomes accustomed to the fact that defecation becomes an arbitrary act.

Pancreas

The pancreas, a parenchymal organ of external and internal secretion, is small in newborns: its weight is about 23 g, and its length is 4-5 cm.Already by 6 months, the mass of the gland doubles, by 1 year it increases 4 times, and by 10 years - 10 times.

In a newborn, the pancreas is located deep in the abdominal cavity at the Tx level, i.e. higher than that of an adult. Due to weak fixation to the posterior wall of the abdominal cavity in a newborn, it is more mobile. In children of early and older ages, the pancreas is at the level of L n. The gland grows most intensively in the first 3 years and in puberty.

By birth and in the first months of life, the pancreas is not sufficiently differentiated, abundantly vascularized and poor in connective tissue. At an early age, the surface of the pancreas is smooth, and by the age of 10-12, tuberosity appears, due to the release of the boundaries of the lobules. The lobes and lobules of the pancreas in children are smaller and few in number. The endocrine part of the pancreas is more developed at birth than the exocrine part.

Pancreatic juice contains enzymes that provide hydrolysis of proteins, fats and carbohydrates, as well as bicarbonates, which create an alkaline reaction of the environment necessary for their activation. In newborns, a small volume of pancreatic juice is released after stimulation, amylase activity and bicarbonate capacity are low. Amylase activity from birth to 1 year increases several times. When switching to a regular diet, in which more than half of the calorie requirement is covered by carbohydrates, the amylase activity rapidly increases and reaches its maximum values by the age of 6-9 years. The activity of pancreatic lipase in newborns is low, which determines the large role of salivary gland lipase, gastric juice and breast milk lipase in fat hydrolysis. The lipase activity of the duodenal contents increases by the end of the first year of life, reaching the adult level by the age of 12. Proteolytic activity of pancreatic secretion in children during the first months of life is quite high, it reaches a maximum at the age of 4-6 years.

The type of feeding has a significant effect on the activity of the pancreas: with artificial feeding, the activity of enzymes in the duodenal juice is 4-5 times higher than with natural one.

In a newborn, the pancreas is small (length 5 - 6 cm, by 10 years - three times more), located deep in the abdominal cavity, at the level of the X thoracic vertebra, in subsequent age periods - at the level of the I lumbar vertebra. It is richly vascularized, intensive growth and differentiation of its structure continues up to 14 years. The organ capsule is less dense than in adults, consists of fine-fibrous structures, and therefore in children with inflammatory edema of the pancreas, its compression is rarely observed. The excretory ducts of the gland are wide, which provides good drainage. Close contact with the stomach, mesentery root, solar plexus and common bile duct, with which the pancreas in most cases has a common outlet to the duodenum, often leads to a friendly reaction from the organs of this zone with a wide irradiation of pain.

The pancreas in children, as in adults, has external and intrasecretory functions. The exocrine function is to produce pancreatic juice. It contains albumins, globulins, trace elements and electrolytes, as well as a large set of enzymes necessary for the digestion of food, including proteolytic (trypsin, chymopsin, elastase, etc.), lipolytic (lipase, phospholipase A and B, etc.) and amylolytic (alpha and beta amylase, maltase, lactase, etc.). The rhythm of pancreatic secretion is regulated by neuro-reflex and humoral mechanisms. Humoral regulation is carried out by secretin, which stimulates the separation of the liquid part of pancreatic juice and bicarbonates, and pancreosimin, which enhances the secretion of enzymes along with other hormones (cholecystokinin, hepatokinin, etc.) produced by the mucous membrane of the duodenum and jejunum under the influence of hydrochloric acid. The secretory activity of the gland reaches the level of secretion of adults by the age of 5 years. The total volume of separated juice and its composition depend on the amount and nature of the food eaten. The intrasecretory function of the pancreas is carried out by the synthesis of hormones (insulin, glucagon, lipocaine) involved in the regulation of carbohydrate and fat metabolism.

Liver in children

Liver size in children

By the time of birth, the liver is one of the largest organs and occupies 1 / 3-1 / 2 of the volume of the abdominal cavity, its lower edge protrudes significantly from under the hypochondrium, and the right lobe may even touch the iliac crest. In newborns, the liver mass is more than 4% of the body weight, and in adults - 2%. In the postnatal period, the liver continues to grow, but more slowly than body weight: the initial liver weight doubles by 8-10 months and triples by 2-3 years.

Due to the different rate of increase in the weight of the liver and body in children from 1 to 3 years of age, the edge of the liver emerges from under the right hypochondrium and is easily palpated 1-3 cm below the costal arch along the midclavicular line. From 7 years old, the lower edge of the liver does not come out from under the costal arch and is not palpable in a calm position; along the median line, it does not go beyond the upper third of the distance from the navel to the xiphoid process.

The formation of liver lobules begins in the fetus, but by the time of birth, the liver lobules are not clearly delineated. Their final differentiation is completed in the postnatal period. The lobular structure is revealed only by the end of the first year of life.

The branches of the hepatic veins are arranged in compact groups and are not interspersed with the branches of the portal vein. The liver is full-blooded, as a result of which it rapidly increases with infections and intoxications, circulatory disorders. The fibrous capsule of the liver is thin.

About 5% of the liver volume in newborns falls on the share of hematopoietic cells, subsequently their number rapidly decreases.

A newborn's liver contains more water, but less protein, fat and glycogen. By the age of 8, the morphological and histological structure of the liver becomes the same as in adults.

Liver functions in the child's body

The liver performs various and very important functions:

produces bile, which is involved in intestinal digestion, stimulates intestinal motor activity and sanitizes its contents;
deposits nutrients, mainly excess glycogen;
carries out a barrier function, protecting the body from exogenous and endogenous pathogenic substances, toxins, poisons, and takes part in the metabolism of medicinal substances;
participates in the metabolism and transformation of vitamins A, D, C, B12, K;
during intrauterine development is a hematopoietic organ.

The formation of bile begins already in the prenatal period, but bile formation at an early age is slowed down. With age, the ability of the gallbladder to concentrate bile increases. The concentration of bile acids in the hepatic bile in children of the first year of life is high, especially in the first days after birth, which causes the frequent development of subhepatic cholestasis (bile thickening syndrome) in newborns. By the age of 4-10 years, the concentration of bile acids decreases, and in adults it increases again.

The neonatal period is characterized by the immaturity of all stages of the hepatic intestinal circulation of bile acids: inadequacy of their capture by hepatocytes, excretion through the tubular membrane, slowing down of bile flow, dyscholia due to a decrease in the synthesis of secondary bile acids in the intestine and a low level of their reabsorption in the intestine. Children produce more atypical, less hydrophobic and less toxic fatty acids than adults. The accumulation of fatty acids in the intrahepatic bile ducts causes an increased permeability of intercellular junctions and an increased content of bile components in the blood. The bile of a child in the first months of life contains less cholesterol and salts, which determines the rarity of stone formation.

In newborns, fatty acids are combined mainly with taurine (in adults, with glycine). Taurine conjugates are more soluble in water and less toxic. The relatively higher content of taurocholic acid in bile, which has a bactericidal effect, determines the rare development of bacterial inflammation of the biliary tract in children of the first year of life.

The enzyme systems of the liver, which provide an adequate metabolism of various substances, are not mature enough at birth. Artificial feeding stimulates their earlier development, but leads to their imbalance.

After birth, the child's synthesis of albumin decreases, which leads to a decrease in the albuminoglobulin ratio in the blood.

In children, transamination of amino acids occurs in the liver much more actively: at birth, the activity of aminotransferases in the child's blood is 2 times higher than in the mother's blood. At the same time, the transamination processes are not mature enough, and the number of essential acids for children is greater than for adults. So, in adults there are 8 of them, children under 5-7 years old need additional histidine, and children in the first 4 weeks of life also need cysteine.

The urea-forming function of the liver is formed by 3-4 months of life, before that, children have high urinary excretion of ammonia at a low concentration of urea.

Children in the first year of life are resistant to ketoacidosis, although they receive a diet rich in fat, and at the age of 2-12, on the contrary, they are prone to it.

In a newborn, the content of cholesterol and its esters in the blood is much lower than that of the mother. After the start of breastfeeding, hypercholesterolemia is noted for 3-4 months. In the next 5 years, the concentration of cholesterol in children remains lower than in adults.

In newborns in the first days of life, insufficient activity of glucuronyl transferase is noted, with the participation of which conjugation of bilirubin with glucuronic acid and the formation of water-soluble "direct" bilirubin occur. Difficulty in the excretion of bilirubin is the main cause of physiological jaundice in newborns.

The liver performs a barrier function, neutralizes endogenous and exogenous harmful substances, including toxins from the intestines, and takes part in the metabolism of drugs. In young children, the detoxifying function of the liver is insufficiently developed.

The functionality of the liver in young children is relatively low. Its enzyme system is especially inconsistent in newborns. In particular, the metabolism of indirect bilirubin released during hemolysis of erythrocytes is not fully carried out, which results in physiological jaundice.

Gallbladder in a child

The gallbladder in newborns is usually hidden by the liver, its shape can be different. Its size increases with age, and by the age of 10-12 years, its length increases by about 2 times. The rate of excretion of gallbladder bile in newborns is 6 times less than in adults.

In newborns, the gallbladder is located deep in the thickness of the liver and has a fusiform shape, its length is about 3 cm. It acquires a typical pear-shaped shape by 6-7 months and reaches the edge of the liver by 2 years.

The bile of children is different in composition from the bile of adults. It is poor in bile acids, cholesterol and salts, but rich in water, mucin, pigments, and in the neonatal period, in addition, in urea. A characteristic and favorable feature of the child's bile is the predominance of taurocholic acid over glycocholic acid, since taurocholic acid enhances the bactericidal effect of bile, and also accelerates the separation of pancreatic juice. Bile emulsifies fats, dissolves fatty acids, improves peristalsis.

Intestinal microflora of a child

During intrauterine development, the intestines of the fetus are sterile. Its settlement with microorganisms occurs first when the mother's birth canal passes, then through the mouth when children come into contact with surrounding objects. The stomach and duodenum contain a meager bacterial flora. In the small and especially the large intestine, it becomes more diverse, the number of microbes increases; microbial flora depends mainly on the type of feeding of the child. When feeding with mother's milk, the main flora is B. bifidum, the growth of which is promoted by (3-lactose of human milk. thus, dyspepsia is more common in children who are bottle-fed.According to modern concepts, the normal intestinal flora performs three main functions:

Creation of an immunological barrier;

Final digestion of food debris and digestive enzymes;

Synthesis of vitamins and enzymes.

The normal composition of the intestinal microflora (eubiosis) is easily disturbed under the influence of infection, improper diet, as well as the irrational use of antibacterial agents and other drugs, leading to a state of intestinal dysbiosis.

Historical data on intestinal microflora

The study of intestinal microflora began in 1886, when F. Escherich described Escherichia coli (Bacterium coli cotipae). The term "dysbiosis" was first introduced by A. Nissle in 1916. Subsequently, the positive role of normal intestinal microflora in the human body was proved by I.I.Mechnikov (1914), A.G. Peretz (1955), A.F. Bilibin (1967), V. N. Krasnogolovets (1968), A. S. Bezrukova (1975), A. A. Vorobyov et al. (1977), I. N. Blokhina et al. (1978), V.G. Dorofeychuk et al. (1986), B. A. Shenderov et al. (1997).

Characteristics of intestinal microflora in children

The microflora of the gastrointestinal tract takes part in digestion, prevents the development of pathogenic flora in the intestine, synthesizes a number of vitamins, participates in the inactivation of physiologically active substances and enzymes, affects the rate of renewal of enterocytes, intestinal hepatic circulation of bile acids, etc.

The intestines of the fetus and newborn are sterile during the first 10-20 hours (aseptic phase). Then colonization of the intestine with microorganisms begins (second phase), and the third phase - microflora stabilization - lasts at least 2 weeks. The formation of the microbial biocenosis of the intestine begins from the first day of life, by the 7-9th day in healthy full-term babies, the bacterial flora is usually represented mainly by Bifidobacterium bifldum, Lactobacillus acidophilus. With natural feeding, B. bifidum prevails among the intestinal microflora, with artificial feeding, L. acidophilus, B. bifidum and enterococci are present in almost equal amounts. The transition to nutrition typical for adults is accompanied by a change in the composition of the intestinal microflora.

Intestinal microbiocenosis

The center of the human microecological system is the intestinal microbiocenosis, the basis of which is the normal (indigenous) microflora, which performs a number of important functions:

Indigenous microflora:

participates in the formation of colonization resistance;
produces bacteriocins - antibiotic-like substances that prevent the reproduction of putrefactive and pathogenic flora;
normalizes intestinal motility;
participates in the processes of digestion, metabolism, detoxification of xenobiotics;
possesses universal immunomodulatory properties.

Distinguish mucoid microflora(M-microflora) - microorganisms associated with the intestinal mucosa, and cavity microflora(P-microflora) - microorganisms localized mainly in the intestinal lumen.

All representatives of the microbial flora with which the macroorganism interacts are divided into four groups: obligate flora (the main intestinal microflora); optional (opportunistic and saprophytic microorganisms); transient (random microorganisms incapable of long-term stay in the macroorganism); pathogenic (pathogens of infectious diseases).

Obligate microflora intestines - bifidobacteria, lactobacilli, full-fledged Escherichia coli, propionobacteria, peptostreptococci, enterococci.

Bifidobacteria in children, depending on age, make up from 90% to 98% of all microorganisms. Morphologically, they represent gram-positive, motionless rods with a clavate thickening at the ends and bifurcation at one or both poles, anaerobic, not forming spores. Bifidobacteria are divided into 11 species: B. bifidum, B. ado-lescentis, B. infantis, B. breve, B. hngum, B. pseudolongum, B. thermophilum, B. suis, B. asteroides, B. indu.

Dysbacteriosis is a violation of the ecological balance of microorganisms, characterized by a change in the quantitative ratio and qualitative composition of the indigenous microflora in the microbiocenosis.

Intestinal dysbiosis is a violation of the ratio between anaerobic and aerobic microflora towards a decrease in the number of bifidobacteria and lactobacilli, normal E. coli and an increase in the number of microorganisms that are found in small numbers or usually absent in the intestine (opportunistic microorganisms).

Methodology for the study of the digestive system

The state of the digestive system is judged by complaints, the results of questioning the mother and the data of objective research methods:

inspection and observation in dynamics;

palpation;

percussion;

laboratory and instrumental indicators.

Child complaints

The most common of these are complaints of abdominal pain, decreased appetite, regurgitation or vomiting, and intestinal dysfunction (diarrhea and constipation).

Questioning the child

The questioning of the mother directed by the doctor makes it possible to clarify the time of the onset of the disease, its connection with the dietary habits and regimen, the past diseases, and the family-hereditary nature. A detailed clarification of feeding issues is of particular importance.

Abdominal pain is a common symptom that reflects a variety of pathologies in childhood. The pains that have arisen for the first time require, first of all, the exclusion of surgical pathology of the abdominal cavity - appendicitis, intussusception, peritonitis. They can also be caused by acute infectious diseases (influenza, hepatitis, measles), viral and bacterial intestinal infections, inflammation of the urinary tract, pleuropneumonia, rheumatism, pericarditis, Schönlein-Henoch disease, periarteritis nodosa. Recurrent abdominal pain in older children is observed in diseases such as gastritis, duodenitis, cholecystitis, pancreatitis, gastric ulcer and duodenal ulcer, ulcerative colitis. Functional disorders and helminthic invasion can also be accompanied by abdominal pain.

Decreased or prolonged loss of appetite (anorexia) in children is often the result of psychogenic factors (overload at school, family conflict, neuroendocrine dysfunction during puberty), including improper feeding of the child (force-feeding). However, usually a decrease in appetite indicates a low secretion of the stomach and is accompanied by disorders of trophism and metabolism.

Vomiting and regurgitation in newborns and infants may be due to pyloric stenosis or pylorospasm. In healthy children of this age, aerophagia, which is observed in violation of the feeding technique, a short frenum of the tongue, and a tight breast in the mother, leads to frequent regurgitation. In children 2-10 years old, suffering from neuro-arthritic diathesis, acetonemic vomiting may periodically occur due to acute reversible metabolic disorders. Vomiting is possible due to damage to the central nervous system, infectious diseases, poisoning.

Diarrhea in children of the first year of life often reflects intestinal dysfunction due to qualitative or quantitative feeding errors, irregularities, overheating (simple dyspepsia) or accompany an acute febrile illness (parenteral dyspepsia), but can also be a symptom of enterocolitis in case of intestinal infection.

Constipation is a rare bowel movement that occurs after 48 hours or more. They can be the result of both a functional disorder (dyskinesia) of the large intestine, and its organic lesion (congenital narrowing, cracks in the anus, Hirschsprung's disease, chronic colitis) or inflammatory diseases of the stomach, liver and biliary tract. Alimentary (eating food, poor in fiber) and infectious factors are of some importance. Sometimes constipation is associated with the habit of delaying the act of defecation and the violation, as a result, of the tone of the lower segment of the colon, and in infants with chronic malnutrition (pyloric stenosis). In children with sufficient weight gain, breastfeeding, stool is sometimes rare due to good digestion and a small amount of toxins in the intestines.

When examining the abdomen, pay attention to its size and shape. In healthy children of different ages, it protrudes slightly above the level of the chest, and subsequently flattens a little. The increase in the size of the abdomen can be attributed to a number of reasons:

hypotension of the muscles of the abdominal wall and intestines, which is especially often observed in rickets and dystrophies;
flatulence, developing with diarrhea of various etiologies, persistent constipation, intestinal dysbiosis, pancreatitis, cystofibrosis of the pancreas;
an increase in the size of the liver and spleen in chronic hepatitis, systemic blood diseases, circulatory failure and other pathology;
the presence of fluid in the abdominal cavity due to peritonitis, ascites;
neoplasm of the abdominal cavity and retroperitoneal space.

The shape of the abdomen also has a diagnostic value: its uniform increase is observed with flatulence, hypotonia of the muscles of the anterior abdominal wall and intestines ("frog" abdomen - with rickets, celiac disease), local swelling in hepatolienal syndrome of various etiologies, tumors of the abdominal cavity and retroperitoneal space. Abdominal sinking can be observed when a child is starving, pyloric stenosis, meningitis, diphtheria. On examination, it is possible to determine the state of the navel in newborns, the expansion of the venous network with cirrhosis of the liver, the divergence of the white line muscles and hernial protrusions, and in emaciated children of the first months of life - intestinal peristalsis, which increases with pyloric stenosis, intussusception and other pathological processes.

Palpation of the abdomen and abdominal organs of the child

Palpation of the abdomen and abdominal organs is best done with the patient in the supine position with slightly bent legs, with a warm hand, starting from the navel, and it is necessary to try to distract the child's attention from this procedure. Superficial palpation is carried out with light tangential movements. It makes it possible to determine the condition of the abdominal skin, muscle tone and tension of the abdominal wall. Deep palpation reveals the presence of painful points, infiltrates, determines the size, consistency, nature of the surface of the lower edge of the liver and spleen, an increase in mesenteric lymph nodes with tuberculosis, lymphogranulomatosis, reticulosis and other diseases, spastic or atonic state of the intestine, accumulation of feces.

Palpation is also possible when the child is upright with a half-bend forward and hands down. At the same time, the liver and spleen are well felt, and free fluid in the abdominal cavity is determined. In older children, bimanual palpation of the abdominal organs is used.

Percussion of the baby's abdomen

Examination of the baby's abdomen

In the last place, the oral cavity and the pharynx of the child are examined. At the same time, attention is paid to the smell from the mouth, the state of the mucous membranes of the cheeks and gums (the presence of aphthae, ulcers, bleeding, fungal overlays, Filatov-Koplik spots), teeth, tongue (macroglossia with myxedema), papillary crimson - with scarlet fever, coated - with diseases of the gastrointestinal tract, "geographical" - with exudative-catarrhal diathesis, "varnished" - with hypovitaminosis B12).

The anal area is examined in younger children in a lateral position, in the rest - in a knee-elbow position. Examination reveals: cracks in the anus, decreased sphincter tone and gaping with dysentery, prolapse of the rectum with persistent constipation or after an intestinal infection, irritation of the mucous membrane with pinworm invasion. Digital rectal examination and sigmoidoscopy can detect polyps, tumors, strictures, fecal stones, mucosal ulceration, etc.

Of great importance in assessing the state of the digestive system is a visual examination of stool. In infants with enzymatic dysfunction of the intestine (simple dyspepsia), dyspeptic stool is often observed, which looks like chopped eggs (liquid, greenish, with an admixture of white lumps and mucus, acidic reaction). Stool is very characteristic for colitis, dysentery. Bloody stools without an admixture of feces against the background of an acutely developed severe general condition can be in children with intestinal intussusception, Discolored stools indicate a delay in the flow of bile into the intestines and is observed in children with hepatitis, blockage or atresia of the bile ducts. Along with the determination of the amount, consistency, color, odor and pathological impurities visible to the eye, the characteristics of the stool are supplemented by microscopic data (coprograms) on the presence of leukocytes, erythrocytes, mucus in the stool, as well as helminth eggs, lamblia cysts. In addition, bacteriological and biochemical studies of feces are carried out.

Laboratory and instrumental research

These studies are similar to those conducted in adults. Of greatest importance is the currently widely used endoscopy, which allows you to visually assess the state of the mucous membranes of the stomach and intestines, make a targeted biopsy, detect neoplasms, ulcers, erosion, congenital and acquired strictures, diverticula, etc. Endoscopic examinations of children of early and preschool age are carried out under general anesthesia. Also used are ultrasound examination of parenchymal organs, radiography of the biliary tract and gastrointestinal tract (with barium), gastric and duodenal intubation, determination of enzymes, biochemical and immunological parameters of blood, biochemical analysis of bile, rheohepatography, laparoscopy with targeted biopsy of the liver and subsequent morphological study ...

Laboratory and instrumental research methods are of particular importance in the diagnosis of diseases of the pancreas, which, due to its location, does not lend itself to direct methods of physical research. The size and contours of the gland, the presence of stones in the excretory ducts, developmental anomalies are detected by relaxation duodenography, as well as retrograde cholangiopancreatography, echopancreatography. Violations of exocrine function observed in cystofibrosis, post-traumatic cysts, atresia of the biliary tract, pancreatitis, are accompanied by a change in the level of basic enzymes determined in blood serum (amylase, lipase, trypsin and its inhibitors), in saliva (isoamylase), urine and duodenal contents. Persistent steatorrhea is an important indicator of insufficiency of exocrine pancreatic function. The intrasecretory activity of the pancreas can be judged on the basis of studying the nature of the glycemic curve.