Significant structural and functional differences in the digestive organs of children compared to those of adults are observed only in the first years of life. The morphofunctional features of the digestive system depend to a large extent on the type of nutrition and food composition. Adequate food for children in the first year of life, especially the first 4 months, is mother's milk. By the time a child is born, the secretory apparatus of the digestive tract is formed in accordance with milk feeding. The number of secretory cells and the enzymatic activity of digestive juices are insignificant. In infants, in addition to parietal, intracellular and cavity digestion, which are not active enough (especially cavity), there is also autolytic digestion due to enzymes in human milk. By the end of the first year of life, with the start of complementary feeding and the transition to definitive nutrition, the formation of one’s own digestive mechanisms accelerates. Complementary feeding at 5-6 months ensures the further development of the digestive glands and their adaptation to the nature of the food.
Digestion in the mouth children of different ages is carried out using mechanical and chemical processing of food. Since teething begins only from the 6th month of life after birth, chewing until this process is completed (up to 1.5-2 years) is ineffective. Oral mucosa in children of the first 3–4 months. life is relatively dry, which is due to insufficient development of the salivary glands and a deficiency of saliva. The functional activity of the salivary glands begins to increase at the age of 1.5–2 months. in 3-4 month old children, saliva often leaks from the mouth due to the immaturity of the regulation of salivation and swallowing of saliva (physiological drooling). The most intensive 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 salivary glands of a newborn secrete very little saliva, from 4-6 months. secretion increases significantly, which is associated with the beginning of complementary feeding: mixed feeding with thicker food is a stronger irritant of the salivary glands. The secretion of saliva in newborns outside feeding periods is very low, and during sucking it increases to 0.4 ml/min.
The glands develop rapidly during this period and by the age of 2 years the structure is close to those of adults. Children under 1 year - 1.5 years old do not know how to swallow saliva, so they experience drooling. During sucking, saliva moistens the nipple and provides a tight seal, which makes sucking more effective. The role of saliva is that it acts as a sealant for the child’s oral cavity, ensuring that the nipple sticks to the oral mucosa, which creates a vacuum necessary for sucking. Saliva, mixing with milk, promotes the formation of looser casein flakes in the stomach.
Sucking and swallowing are innate unconditioned reflexes. In healthy and mature newborns, they are already formed at the time of birth. When sucking, the baby's lips tightly grasp the nipple. The jaws squeeze it, and the communication between the oral cavity and the outside air stops. Negative pressure is created in the child’s mouth, which is facilitated by lowering the lower jaw along with the tongue down and back. Then breast milk enters the rarefied space of the oral cavity.
The larynx in infants is located differently than in adults. The entrance to the larynx is located high above the infero-posterior edge of the velum palatine 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.
Digestion in the stomach.
The shape of the stomach, characteristic of adults, is formed in a child by the age of 8-10 years. The cardiac sphincter is underdeveloped, but the muscular layer of the pylorus is pronounced, so regurgitation and vomiting are often observed in infants. The capacity of a newborn's stomach is 40-50 ml, by the end of the first month 120-140 ml, by the end of the first year 300-400 ml.
In early infants, the volume of gastric juice is not large, because the complex reflex phase of gastric secretion is weakly expressed, the receptor apparatus of the stomach is poorly developed, mechanical and chemical effects do not have a pronounced stimulating effect on the secretion of the glands.
The pH of the gastric contents of a newborn baby ranges from slightly alkaline to slightly acidic. During the first day, the environment in the stomach becomes acidic (pH 4 - 6). The acidity of gastric juice is created not by HCl (there is a small amount of free HCl in the juice), but by lactic acid. The acidity of gastric juice is provided by lactic acid until approximately 4-5 months of age. The intensity of HCl secretion increases approximately 2 times with mixed feeding and 2-4 times when switching to artificial feeding. Acidification of the stomach environment is also stimulated by proteolytic enzymes.
First 2 months During the life of a child, the main role in the breakdown of proteins is played by fetal pepsin, followed by pepsin and gastrixin (enzymes of an adult). Fetal pepsin has the property of curdling milk.
The activity of gastric pepsins for plant proteins is quite high from the 4th month of a child’s life, and for animal proteins - from 7 months of age.
In the slightly acidic environment of the stomach of young infants, proteolytic enzymes are inactive, due to this, various milk immunoglobulins are not hydrolyzed and are absorbed in the intestines in their native state, providing the proper level of immunity. In the stomach of a newborn, 20-30% of incoming proteins are digested.
Under the influence of saliva and gastric juice in the presence of calcium ions, caseinogen protein dissolved in milk, lingering in the stomach, turns into insoluble loose flakes, which are then exposed to proteolytic enzymes.
Emulsified milk fats are well broken down by gastric lipase from the moment the child is born, and this lipase is filtered from the capillaries of the gastric mucosa. Lipase from the baby's saliva and breast milk also take part in this process; breast milk lipase is activated by lipokinase from the baby's gastric juice.
Milk carbohydrates are not broken down in the child’s stomach, since gastric juice does not contain the corresponding enzymes, and salivary alpha-amylase does not have this property. In the slightly acidic environment of the stomach, the amylolytic activity of the baby's saliva and mother's milk can persist.
The activity of all gastric enzymes reaches adult norms at 14-15 years of age.
Stomach contractions in a newborn, continuous, weak, but with age they intensify, periodic gastric motility appears on an empty stomach.
Human milk stays in the stomach for 2-3 hours, nutrient mixture with cow's milk - 3-4 hours. Regulatory mechanisms are immature, local mechanisms are somewhat better formed. Histamine begins to stimulate the secretion of gastric juice from the end of the first month of life.
Digestion in the duodenum carried out with the help of enzymes of the pancreas, the duodenum itself, and the action of bile. In the first 2 years of life, the activity of proteases, lipases and amylases of the pancreas and duodenum is low, then it increases rapidly: the activity of proteases reaches its maximum level by 3 years, and lipases and amylases by 9 years of life.
The liver of a newborn and infant is large; a lot of bile is secreted, but it contains little bile acids, cholesterol and salts. Therefore, during early complementary feeding in infants, fats may be insufficiently absorbed and appear in the feces of children. Due to the fact that newborns excrete little bilirubin in their bile, they often develop physiological jaundice.
Digestion in the small intestine. The relative length of the small intestine in a newborn is large: 1 m per 1 kg of body weight, and in adults it is only 10 cm.
The mucous membrane is thin, richly vascularized and has increased permeability, especially in children of the first year of life. Lymphatic vessels are numerous and have a wider lumen than in adults. Lymph flowing from the small intestine does not pass through the liver, and absorption products enter directly into the blood.
Enzyme activity the mucous membrane of the small intestine is high - membrane digestion predominates. Intracellular digestion also plays a significant role in digestion. Intracavitary digestion in newborns is not formed. With age, the role of intracellular digestion decreases, but the role of intracavitary digestion increases. There is a set of enzymes for the final stage of digestion: dipeptidases, nucleases, phosphatases, disaccharases. The proteins and fats of human milk are digested and absorbed better than cow's milk: the proteins of human milk are absorbed by 90-95%, and those of cow's milk by 60-70%. Features of protein absorption in young children include the high development of pinocytosis by epithelial cells of the intestinal mucosa. As a result, milk proteins in children in the first weeks of life can pass into the blood in a slightly changed form, which can lead to the appearance of antibodies to cow's milk proteins. In children older than one year, proteins undergo hydrolysis to form amino acids.
A newborn baby is able to absorb 85-90% fat human milk. However lactose Cow's milk is absorbed better than women's milk. Lactose is broken down into glucose and galactose, which are absorbed into the blood. The inclusion of pureed fruits and vegetables in the diet enhances the secretory and motor activity of the small intestine. When switching to definitive nutrition (typical of an adult), the production of invertase and maltase increases in the small intestine, but the synthesis of lactase decreases
Fermentation in the intestines of infants complements the enzymatic breakdown of food. There is no rotting in the intestines of healthy children in the first months of life.
Suction is closely related to parietal digestion and depends on the structure and function of the cells of the superficial layer of the mucous membrane of the small intestine.
The peculiarity of absorption of hydrolysis products in children in early ontogenesis is determined by the peculiarities of food digestion - mainly membrane and intracellular, which facilitates absorption. Absorption is also facilitated by the high permeability of the mucous membrane of the gastrointestinal tract. In children of different years of life, absorption in the stomach occurs more intensively than in adults.
Digestion in the large intestine. The intestines of a newborn contain original feces (meconium), which includes the remains of amniotic fluid, bile, exfoliated intestinal epithelium, and thickened mucus. It disappears from feces within 4-6 days of life. Motor skills in young children are more active, which contributes to frequent bowel movements. In infants, the duration of passage of food gruel through the intestines ranges from 4 to 18 hours, and in older children - about a day. High motor activity of the intestine, combined with insufficient fixation of its loops, determines the tendency to intussusception.
Defecation in children in the first months of life is involuntary - 5-7 times a day; by the age of one year it becomes voluntary and occurs 1-2 times a day.
Microflora of the gastrointestinal tract The intestines of the fetus and newborn are sterile for the first 10–20 hours (aseptic phase). Then the colonization of the intestines with microorganisms begins (the second phase), and the third phase - stabilization of the microflora - lasts at least 2 weeks. The formation of the intestinal microbial biocenosis begins from the first day of life; by the 7th–9th day in healthy full-term infants, the bacterial flora is usually represented mainly by Bifidobacterium bifidum, Lactobacillus acidophilus
The microflora of the gastrointestinal tract in a newborn baby mainly depends on the type of feeding; it performs the same functions as the microflora of an adult. For the distal part of the small intestine and the entire colon, bifid flora is the main one. Stabilization of microflora in children ends by the age of 7 years.
Human milk contains p-lactose, which is broken down more slowly than cow's milk a-lactose. Therefore, in the case of breastfeeding, part of the undigested β-lactose enters the large intestine, where it is broken down by bacterial flora, and thus normal microflora develops in the large intestine. When feeding cow's milk early, lactose does not enter the large intestine, which may be the cause of dysbiosis in children.
Neuroendocrine activity of the gastrointestinal tract.
Regulatory peptides produced by the endocrine apparatus of the gastrointestinal tract in the fetus stimulate the growth and differentiation of mucous membranes. The production of enteral hormones in a newborn increases sharply immediately after the first feeding and increases significantly in the first days. The formation of the intramural nervous apparatus, which regulates the secretory and motor activity of the small intestine, is completed at 4-5 years. In the process of maturation of the central nervous system, its role in regulating the activity of the gastrointestinal tract increases. However, conditioned reflex secretion of digestive juices begins in children already in the first years of life, as in adults, subject to a strict diet - a conditioned reflex for a while, which must be taken into account.
Hydrolysis products absorbed into the blood and lymph are included in the process of anabolism.
Some of the many benefits of breastfeeding are ease of feeding. Each part of the digestive tract has specific functions that work to transport and digest foods important to your baby's growth. The digestion of breast milk has important functions ranging from absorbing protective antibodies that fight bacteria and viruses to creating healthy gut bacteria.
Anatomy and physiology of the children's digestive tract
Let's start by learning about the anatomy of baby digestion from the moment food enters the mouth until it goes into your baby's diaper, and the functions that happen along the way. The accessory organs are extremely important for proper digestion and will be discussed below.
- Mouth. Children's mouths act as food intake and are also where the digestion of certain nutrients begins. Some newborns may have difficulty latching or problems associated with conditions such as cleft lip or cleft palate.
- Esophagus. It is a tube that connects the mouth to the stomach and has two main jobs - to push food or liquid from the mouth into the stomach and to stop the backflow of stomach contents.
- Stomach. It is responsible for storing ingested food, combining and breaking down food, and regulating the release of stomach contents into the duodenum, the first part of the small intestine. Digestion occurs in three phases - cephalic (initiated by the vagus nerve when seeing something and smelling any food), gastric (triggered by food consumption and controlled by gastrin) and intestinal (regulated by hormones secreted in the small intestine).
- Small intestine. It is a tubular organ divided into three parts - the duodenum, small intestine and ileum. It does a great job as it is responsible for digesting and absorbing nutrients, vitamins, minerals, fluids and electrolytes. Essentially, acidic, partially digested food from the stomach combines with basic secretions from the pancreas, liver and intestinal glands. Digestive enzymes from these secretions are responsible for much of the digestion process in the small intestine - they break down breast milk proteins into amino acids; breast milk carbohydrates into glucose and other monosaccharides; and breast milk fats into glycerol and fatty acids. The intestinal wall must be very strong to cope with the work it does. Its strength comes from the fact that it has four different layers - serous, muscular, submucosal and muscularis. The surface of the intestine is significantly increased due to the presence of villi and microvilli, with the help of which the final products of digestion are absorbed.
- Colon. It curves upward from the end of the small intestine, through the abdominal cavity and into the rectum. Mainly responsible for the absorption of water and electrolytes.
- Straight. The O'Beirne sphincter regulates the flow of waste from the sigmoid colon into the rectum, which is the storage area for digestive waste. The internal and external anal sphincters regulate the flow of fecal matter from the rectum.
Accessory organs of the children's digestive tract
In addition to the digestive tract itself, there are several accessory organs that are important in the digestion of food. These include:
- Salivary glands. The salivary glands in the mouth produce salivary enzymes. The submandibular, sublingual and parotid glands produce saliva, which contains amylase, the enzyme responsible for initiating the digestion of carbohydrates.
- Liver. The liver is actually the largest organ in the body. It is responsible for protein and carbohydrate metabolism and storage of glycogen and vitamins. It also helps in the formation, storage and elimination of bile and plays a role in fat metabolism. The liver is where toxins are captured and sometimes stored to protect the rest of the body.
- Gallbladder. The gallbladder is a tiny sac that rests on the lower region of the liver. This is where bile (which consists of salts necessary for digestion and absorption of fats) is collected from the liver. The "Sphincter of Oddi" regulates the flow of bile into the duodenum. Like the liver, the gallbladder helps in the composition, storage and removal of bile and plays a role in the digestion of fat.
- Pancreas. The pancreas produces alkaline (or neutral) secretions that take part in displacing acidic, partially digested food (also called chyme) from the stomach. These secretions contain enzymes that are necessary for the absorption of fats, proteins and carbohydrates. Although these digestive enzymes are produced in the "exocrine" pancreas, many people are more familiar with the hormone insulin, which is produced in the "endocrine" portions of the pancreas.
Breast milk also contains enzymes that aid in digestion, such as amylase, lipase and protease. This is important for infants because digestive enzymes are not present at adult levels until infants reach six months of age.
In general, the parts of the digestive system work together to take in food, transport it further into the digestive tract system, mechanically and chemically break it down and absorb nutrients, and then destroy excess material as waste.
Differences between the gastrointestinal system of infants and adults
There are several anatomical as well as functional differences between the digestive tract of infants and adults.
- Differences in the head and neck. A baby's tongue is larger in relation to the mouth, and there are additional fat pads on the sides of the tongue that help with sucking. Additionally, the larynx, or voice box, is higher in infants than in adults, and the epiglottis lies above the soft palate to provide additional airway protection.
- Differences in the esophagus. In a newborn baby, the esophagus is about 11.5 cm long (versus 24 cm in adults), and the lower esophageal sphincter is about 1 cm in diameter. Quite often at birth, a thin suction tube is passed through the esophagus to ensure that this sphincter is open. Esophageal defects that are not uncommon include atresia (a condition in which the esophagus is completely closed) and fistulas (a condition in which there is a connection between the esophagus and another organ such as the trachea).
- Differences in the stomach. A newborn's stomach can only hold 1/4 and 1/2 cups of liquid (versus 14 cups in adults!). The digestive activity of the stomach is the same in infants and adults. The gastric glands of the stomach include parietal cells, which produce hydrochloric acid and intrinsic factor. The chief cells in these glands secrete pepsinogen, which is converted into pepsin, breaking down proteins in the gastric juice. Surprisingly, bowel sounds already exist within an hour of birth, and parietal cells begin to function immediately after birth. The pH of the stomach is less than 4 during the first 7-10 days of life.
- Small intestine. There are also anatomical differences in the small intestine. In an infant it is from 255 to 305 cm in length, and in an adult it is from 610 to 800 cm.
- Colon. At first, the baby's intestines are sterile. However, within a few hours E. Coli, Clostridium and Streptococcus are established. The collection of bacteria in the tract is necessary for digestion and the production of vitamin K, a vitamin that is important for blood clotting. Because it takes some time for this to happen after birth, babies are usually given a vitamin K shot at birth.
- Emptying. The first stool passed is called meconium. Meconium is thick, sticky and resinous. It is black or dark green in color and is made up of mucus, a white cheesy substance present on the baby's skin, lanugo (fine hair present on the baby's skin), hormones and carbohydrates. It is imperative that the newborn has bowel movement within 24 hours of birth.
Healthy Gut Bacteria
In recent years, we've learned more about gut bacteria and their importance in everything from physical health to emotional well-being. Breastfeeding usually results in colonization of the colon with the right balance of healthy bacteria. Rather than relying on enzymes only in the digestive tract, healthy gut bacteria are very important for the proper digestion of foods and the resulting absorption of nutrients needed for growth and development. As we learn more about how the infant gut microbiome relates to breastfeeding, it is likely that current breastfeeding recommendations will become even stronger.
A child's digestive tract differs from an adult's in several ways and is a process involving many different organs and several steps. From providing digestive enzymes to creating healthy gut bacteria, breast milk can get your baby off to a healthy start.
During the first year of a child’s life, both young and experienced parents are faced with the problem of increased anxiety and the occurrence of “intestinal colic.” This prompts them to ask the question: “How to normalize intestinal function in a baby?”
Features of the newborn's intestines
The baby is born with sterile intestines. After birth, the child enters an environment that is populated by a large number of microorganisms. Among them are beneficial bacteria that are involved in the digestion process. There are conditionally pathogenic agents that can lead to disease under certain conditions. During the first two weeks, there is a struggle between microorganisms for the right to “settle” in the newborn’s intestines.
Normally, the microflora consists mainly of bifidobacteria. In addition, lactobacilli, E. coli, and enzymes are necessary for intestinal function.
The main source of beneficial bacteria is breast milk. When breastfeeding, the formation of beneficial microflora in the intestines occurs faster.
Functional bowel disorders
While in the mother's tummy, the child did not engage in the process of digesting food, but received everything he needed from the mother's blood through the umbilical cord. Once born, he needs to deal with it on his own. The stomach and intestines have to work together and harmoniously.
How to normalize intestinal function to avoid both diarrhea and constipation? The stomach needs to produce the necessary enzymes in time to digest incoming breast milk. The intestines must move the contents at an optimal speed. If this happens quickly, diarrhea will occur, and if it happens slowly, constipation will occur. A small organism must simultaneously establish all the functions of the gastrointestinal system. The failure of one system leads to failure in another.
How to normalize the intestines to avoid colic
Colic is not a disease, but a temporary functional disorder.
During feeding, the intestines automatically contract and spasms occur. The child is worried and begins to worry. As a result, a large amount of air enters the stomach. Painful sensations and a feeling of fullness appear. This entails regurgitation or vomiting, accumulation of gases in the intestines. Constipation may occur.
In such situations, the child’s entire body suffers. Motor excitement appears. The baby screams and “squirms.” He sees the only peace for himself in the process of sucking. There is a misconception that the baby is hungry all the time because he sucks on the breast, a pacifier, and his fist.
Proper and healthy nutrition
Breast milk is the best feeding option. A different diet will only aggravate the situation, increasing the manifestations of spasms and colic.
How to improve the intestines and smooth out a difficult period of life for it? Before eating, you need to place the baby on his stomach. This is a kind of massage for better removal of gases and strengthening muscles.
For some time, you should feed the baby on demand. Although the breaks between meals should be at least 2 hours. During this time, a sufficient amount of enzymes will be released and the milk will be digested. And the food continuously entering the stomach will begin to ferment, which will lead to leucorrhoea and regurgitation.
After eating, the baby should be held upright until burping occurs. Then lay it on its side. In this position, the risk of vomit entering the respiratory tract is minimal. It is easier for milk to flow from the stomach further into the intestines.
Restoring bowel function in infants
An infant should have bowel movements every day. Usually it occurs as many times as the child takes food. If bowel movements occur a couple of times a day, and the baby is not restless, this is also considered normal.
When there is no stool for more than two days, it’s time to help the child empty his intestines. Placing it on your stomach or massaging it in a clockwise circular motion, placing a diaper or heating pad on your stomach with an iron will help.
If such measures do not help, you should use a tube to remove gases or do an enema. The end of the tube should be lubricated with cream, carefully insert it into the anus 5 cm, holding it with your hand. With your free hand, you can apply light pressure, massage around the navel, bend and straighten the baby’s legs, pressing them on the tummy. Two or three doses should be taken within 5-10 minutes. Stools should appear and accumulated gases should be released.
If necessary, an enema is given with cool water in a volume of about 200 ml, placing the child on his left side.
Drugs to normalize intestinal function in a baby
Modern pharmaceuticals know how to normalize the intestinal function of suffering babies and make life easier for their mothers. There are many harmless plant-based products available. They are easy to use, have a pleasant taste and smell, which is important if you need to give medicine to a screaming baby.
How to “tune” a child’s digestion?
Caring for a baby implies not only love, but also an understanding of how the little person’s body works and what processes occur in it. This knowledge is necessary to properly organize the baby’s nutrition, as well as to respond to the nuances of his life without panic or surprise.
While the baby is waiting to be born in the womb, his digestive system is in a state of inactivity. The embryo receives nutrition through the placenta. As soon as a child is born, there is a need to obtain nutrients in the traditional human way - through the mouth. The baby’s mind already has a sucking reflex, but it needs to be “launched.” This is why early (ideally in the first half hour of life) attachment of the baby to the mother’s breast is so important. If you give a newborn a nipple first, the muscles of the oral cavity will remember exactly its shape and the so-called “nipple” sucking will be formed. In the future, when breastfeeding, the mother will have problems - the child will injure the nipples or completely refuse the breast.
How to improve digestion in a baby?
The volume of a newborn's stomach is only 30 ml. When the baby begins to grow, the capacity of the stomach will also increase - at the age of 1 month it will be about 100 ml, at 3 months - 150 ml, at six months - 2000 ml, by 1 year - 250 ml. Mom needs to understand that such a small organ should not be overfilled. Overfeeding will stretch the walls of the stomach and will contribute to overeating in the future.
Breast milk (and in the first days colostrum, which is more nourishing, high in protein, and very valuable in energy) is the ideal food for a child. 10 ml of colostrum per feeding in the first days of life will completely satisfy the newborn’s need for food. Along with milk, antibodies to many infectious diseases (those that the mother has suffered during her life) enter the baby’s body. Thus, the child receives a kind of vaccination. In addition, milk is the most easily digestible and digestible food. This is important, since the digestive process in newborns is just developing, and very few enzymes are produced in the stomach for digesting food.
One of the important components of the digestive process is saliva. In a newborn, due to the poor development of the salivary glands in the oral cavity, there is little of it. Dry mucous membranes are very susceptible to minor damage and infection. In addition, the antibodies (class A immunoglobulins) that protect it are not produced at all in the first month of life. Therefore, babies very often develop thrush. As they grow older, the production of saliva will increase, but the swallowing reflex will not form immediately, so at 3–4 months the child will experience frequent drooling. To prevent saliva from irritating the skin, it must be wiped off periodically.
The stomach in young children is horizontal until the child begins to walk. Food stays in it for an average of 2.5–3 hours. This must be taken into account when organizing feeding intervals. Artificial formula takes longer to digest than breast milk - on average 3-4 hours.
The newborn's intestines are very long, and the muscles of the internal organs are still weak. This is why children often experience constipation in the first 3 months of life. Later the stool returns to normal. Typically, children in the first months of life have bowel movements 2–4 times a day. By the end of the first year, 1-2 times a day is considered normal. Be prepared for the fact that in the first two days of life, thick, very dark-colored stool will come out of the baby’s intestines. This is meconium - it accumulated in the baby’s body throughout the entire intrauterine development.
The digestive system in children is significantly different from that in adults. That’s why some foods need to be given to children from a certain age, and then only in doses. For example, mushrooms. How does this system of a child’s body change with age?
Age-related features of the digestive system
A characteristic feature of the children's digestive system is the tenderness of the mucous membranes of the gastrointestinal tract, abundant blood supply and underdevelopment of their elasticity.
The glands of the children's intestines and stomach before school age are not fully developed and are few in number. Therefore, a child’s gastric juice has a low concentration of hydrochloric acid, and this reduces the bactericidal properties of digestion and, of course, increases the sensitivity of children to gastrointestinal infections. The number of glands in the stomach increases rapidly until the age of 10, and at 14-15 years it almost corresponds to the level of an adult.
And the composition of gastric juice enzymes changes in the first years of life. Thus, the enzyme chymosin, which acts on milk proteins, is actively produced by the glands of the stomach in the first 2 years of life, then its production decreases. In adults, by comparison, this enzyme is almost absent. The activity of other gastric juice enzymes increases by the age of 15-16 years and at this age already reaches adult levels. An age-related feature of a child’s digestive system is that up to 10 years of age, absorption processes are very active in the stomach. In adults, these processes occur only in the small intestine.
That is, the development of the digestive organs in children occurs in parallel with the development of the whole organism. And this development is divided into the periods of the first year of life, preschool age and adolescence.
At this time, the work of the digestive organs is controlled by the nervous system and depends on the state of the cerebral cortex. In the process of developing the digestive system, children easily develop reflexes regarding the time of eating, its composition and quantity.
Anatomical and physiological features of the digestive organs in young children
The esophagus in young children has the shape of a spindle. It is short and narrow. In children one year of age, its length is 12 cm. There are no glands on the esophageal mucosa. Its walls are thin, but it is well supplied with blood.
The stomach in young children is located horizontally. And as the child develops, he takes a vertical position. By the age of 7-10 years, the stomach is already positioned as in adults. The gastric mucosa is thick, and the barrier activity of gastric juice is low compared to adults.
The main enzyme in gastric juice is rennet. It ensures milk curdling.
The pancreas of a young child is small. For a newborn it is 5-6 centimeters. Already at 10 years old she will triple in size. This organ is well supplied with blood vessels. The pancreas produces pancreatic juice.
The largest organ of the digestive system at an early age, occupying a third of the abdominal cavity, is the liver. At 11 months its mass doubles, and by 2-3 years it triples. The capacity of the liver at this age is quite low.
The gallbladder at an early age reaches a size of 3 centimeters. It takes on a pear-shaped shape by 7 months. Already at 2 years of age, the child’s gallbladder reaches the edge of the liver.
For children under one year old, substances supplied with mother's milk are of great importance. With the introduction of complementary foods, the mechanisms of the child's enzyme systems are activated.
Anatomical and physiological features of the digestive organs in preschool children
During preschool age, children continue to grow and develop their digestive organs. However, due to different rates of general growth and development up to 3 years, the edge of the liver extends from the area of the right hypochondrium and is easily palpated 1-2 cm below the arch of the ribs.
The baby's pancreas develops very actively until the age of 1 year, and then a leap in its development occurs at 5-7 years. In terms of its parameters, this organ reaches adult levels only by the age of 16. The same rates of development are characteristic of the child’s liver and all parts of the intestines.
Due to the development of the digestive organs, children under 3 years of age need dietary restrictions.
It should be noted that in preschool children, acute digestive disorders are very common. However, they most often occur more easily than in children in their first year of life. It is important for parents of preschool children to feed their children properly, taking into account the growth of their teeth, the diet, and a balanced diet. Foods that are difficult for the stomach, which the stomach of an adult can easily handle, are often rejected by the child’s body, causing indigestion.
Digestion in adolescents and its features
During adolescence, the digestive organs are already well developed. They function actively, and the digestion process itself is almost no different from adults. The frequency of bowel movements in adolescence is 1-2 times a day.
At the age of 12, a bump appears on the previously smooth surface of the pancreas. These tubercles are caused by the secretion of the lobules of the pancreas.
Children's livers are also actively enlarging. So, by the age of 8, it grows 5 times compared to its size at birth, and by the age of 16-17, its weight increases 10 times. It should be noted that from the age of 7 years, the lower edge of this organ is not palpable in the supine position. By the age of 8 years, the histological structure of the child’s liver is the same as that of adults. By the age of 10-12 years, the gallbladder almost doubles in size.
It is necessary to take into account the specific structure of the gastrointestinal tract of adolescents when organizing their nutrition. We are talking about daily compliance with the diet and its organization at school. After all, nutritionists state that in order to develop a healthy digestive system, school-age children need to eat four times a day due to their energy expenditure.
Digestive disorders in children
Problems with the gastrointestinal tract in children occur quite often. This is especially true at an early age. Diarrhea or constipation not only spoils the well-being of children, but also forces parents to adjust their diet. If your child experiences such disorders frequently during preschool age, then you should not rely on yourself, but rather consult a good, experienced pediatrician. Parents should also see a doctor because only a doctor can determine the onset of a serious pathology.
Diarrhea can be caused by infection, and functional diarrhea can even be caused by child stress. Then his stool is mushy or liquid. It occurs 2-4 times a day, but without admixtures of pus and blood.
Unwashed hands and dirty water, even accidentally swallowed while bathing, stale food or insufficiently thermally processed food are the main causes of intestinal infections in children.
Symptoms of intestinal infections are vomiting and frequent diarrhea, stomach pain and fever. When a child experiences diarrhea, only a doctor can rule out surgical pathology and infection in the intestines.
The main danger of childhood intestinal infections is dehydration. A child with diarrhea loses a lot of fluid, but cannot drink enough due to vomiting.
Preventing intestinal infections means following simple hygiene rules:
- Drink only boiled or mineral table water.
- Washing your hands before eating and after using the toilet.
- It is taboo to buy products from spontaneous markets, especially those sold from the ground. Lack of sanitary control can cause serious digestive problems. For example, milk from leukemic cows is often sold in such markets.
- Proper storage of products and control over their expiration dates.
- Thoroughly wash vegetables and fruits before eating them.
Diet plays a huge role in the prevention of digestive disorders. Children should be fed mother's milk until at least six months of age. This is their immunity and a kind of vaccination for the gastrointestinal tract. Children under three years of age should not be fed fatty and spicy foods, chocolate and rich broths. Food for such babies should be steamed. It's good if you bake it rather than fry it.
An equally common digestive problem in children is constipation. It is usually provoked by an early transition to artificial feeding, the introduction of complementary foods ahead of schedule, or a lack of fluid in the child.
Parents should be aware of another feature of constipation in children. This is suppressing the urge to defecate outside the home. This phenomenon is typical for shy children and can occur, for example, during the period of adaptation to kindergarten. Over time, this negative habit leads to hardening of stool and injury to the rectal mucosa. The consequence of this is the fear of defecation.
Constipation can also be the result of chronic pathologies of the digestive and endocrine systems, and frequent use of certain medications. Therefore, parents need to monitor their baby’s stool, changes in his behavior and promptly seek help from pediatricians in order to avoid the development of chronic digestive ailments.
Especially for - Diana Rudenko
