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Lecture N10
Embryogenesis, anatomic and physiological features of digestive system in children.
Semiotics of gastrointestinal diseases
The germ of digestion system appears by 7-8 day of intra-uterine life. The initial intestine, which
by 12 day shares on 2 parts, is formed of an endoderm. The digestive tract is formed of an
intraembrionic part of an initial intestine. In the process of embrional development the formation
of an ileac diverticulum– Meckel’s diverticulum is possible. By the end of 1 month the initial
intestine becomes closed like a tube. From anterial part of a digestive tube the pharynx, an
esophagus, a stomach and an initial part of duodenun with germs of a pancreas and a liver
develop. The meddle part of a digestive tube gives the germ of the rest of an intestine, and
posterior part – for all parts of colon. In the beginning the lumen of a digestive tube is filled with
cellular mass. On 3-4 month digestive glandules start to function and recanalisation occurs. The
infringement of process of canalization conducts to formation of stricture of a gastrointestinal
tract.
The digestive tract represents by mouth, pharynx, esophagus, stomach, large and small intestine.
Digestive glandules – the liver and a pancreas produce secrets for processes of digestion.
Morphofunctional features.
The oral cavity at the child is rather small. There are some adaptations to the act of suction – the
big tongue, sucking pads of Bish of cheeks, duplicators of gun mucosa. The mucosa of an oral
cavity is tender, thin, richly supplied with blood vessels, dry because of deficiency of saliva.
Development of sialadens comes to an end by 3-4 months, since this moment the physiological
hypersalivation is observed. The entrance to larynx in newborn is posed highly; therefore the
child can breathe and suck in the same moment.
The esophagus has tender thin mucosa, well supplied with blood vessels. Glandules of an
esophagus in newborn are completely absent, muscular and elastic tissue are badly advanced.
The entrance to an esophagus in newborn is posed highly – at a level of 3-4 cervical vertebras, in
the adult at a level of 7th vertebra. The exit from an esophagus at any age is on the level of 10-11
thoracic vertebra. For definition of length of an esophagus used Bishoff’s formula. Length of an
esophagus = 1/5 lengths of a body + 6,3 cm
The stomach in children of breast age is posed horizontally. The cardiac part of a stomach is
advanced insufficiently; therefore in yang children often regurgitations are possible. Pyloric part
of a stomach is advanced well, and sometimes at its excessive development the pylorospasm is
observed.
Capacity of a stomach in newborn is 30-35 ml, by the end of the first year - 250-300 ml, by 8
years -1000 ml. One-time volume of nutrition for the child of the first year of life is possible to
count under the formula 30 (n+1), n - number of months. Mucosa is tender, it is rich of blood
vessels, contains few digestive glandules. Insufficient production of gastric juice with a low
acidity is marked. The muscular layer is badly advanced, the flaccid peristalsis is marked, and
the gastric air bubble is enlarged. By 2 years structural and functional peculiarities of stomach
approximate to those in adults.
The small intestine consists from duodenum, jejunum and ileum. In comparison with adults, a
small intestine in children till 5 years:
- has rather big length and the big mobility, therefore invaginations are frequently possible
- intestine lay more compactly
- a lot of gases contains
- the high permeability of an intestinal epithelium is marked, underproteolytic proteins can
be soaked up, causing a sensibilization
- weak development of muscular and elastic fibers of an intestinal wall
- mucosa is thin, dry, it is rich of blood vessels
-
villi and furrows of a mucosa are well advanced
there is secretory insufficiency that promotes penetration into a blood of not digestive
components of nutrition, toxins and microorganisms
insufficiencies of ileocecal valve promotes to entering bacterial flora of a colon to an
ileum
The large intestine is situated higher and has the length peer to body height of the child. In
newborns is not presents of haustration till 6 months. Caecum it is posed highly, in newborn it is
just under the liver. The appendix has widely open entrance, has the big mobility and can
localise in any part of an abdominal cavity, but most frequently in retrocecal position that it is
necessary to take into account at diagnostics of appendicitis. The transversal part of a colon in
newborns is in epigastria. The sigmoid colon descendes to a small pelvis only after 5 years, till 7
years it is mobile because of presence of a long mesentery. The mucosa of a rectum is badly
fixed, its submucosa is well advanced, and therefore rectal prolapse is possible.
The motility of a small and large intestine in children is increased. The intestine of a fetus and an
intestine of newborn are sterile. In the first day after a birth Meconium – first-born feces appears.
Meconium consists from amniotic water, slime, cholic pigments, epitelium. Settling of an
intestine by a normal microflora begins with the first hours of life and usually comes to an end
by 7-10 day. In this time interval the transitional dysbacteriosis of an intestine is observed.
The pancreas in the first months of life is insufficiently differentiated, posed deeply in an
abdominal cavity. Its surface is smooth. The lobular structure of a pancreas appears only by 12
years.
The liver in children has rather big sizes, 4 % from mass of a body in newborn, 2 % in the adult.
The lower edge of a liver from the right hypochondrium is on 1-2 cm in children till 3 years. In
children till 7 years the edge of a liver on a middle line is lower than the upper third of distance
from a xiphoid process to umbilicus. Parenchyma of a liver it is poorly differentiated, the lobular
structure is tipical only by the end of the first year of life. The liver is sanguineous, is easily
enlarged at infectious diseases, intoxication, infringements of a circulation. Bile is rather poor of
cholic acids, but has high bactericidal properties because of prevalence of taurocholic acids on
glycocholic in it.
The liver deposits nutrients, basically, a glycogen, and also lipids and proteins. Albumins, beta
and an alpha – globulins, a ceruloplasnin, a transferrin, a thrombinogen, and fibrinogen are
synthesized in a liver. In children hemorrhagic symptoms at liver damage develops more often.
Semiotics of gastrointestinal diseases
Gastrointestinal diseases occupy 2-nd place on prevalence in children after respiratory diseases.
Conceptions about pathogenes of many gastrointestinal diseases have essentially changed during
last years.
Symptoms
Abdominal pain
The reasons causing a pain are various. They can be connected to superficial damage: billiary
dyskinesia, helminthiases, a meteorism or can be connected with a serious pathology: an
intestinal obstruction, appendicitis, peritonitis. The abdominal pain is not always connected with
pathology of digestion. A sources of abdominal pains can be: pathology of kidneys, diseases of
backbone, inflammatory processes of genitals in girls, pain can be caused by psychological
problems at school and in family.
Localization of the pain. Children till 3 years localize a pain badly and at pain of any localization
show to center of abdomen. Division of abdomen into 9 areas is received: the right and left
hypochondrium, epigastric area, right and left flanks, paraumbilical area, the right and left iliac
areas, suprapubic area. Pain in right hypochondrium are characteristic of diseases of liver,
billiary tract, right kidney, in left hypochondrium – of pathology of pancreas, spleen, left kidney.
Pain in epigastria is frequently observed at gastritis, esophagitis. Pain in paraumbilical area can
be at helminthiases, higher of umbilicus right-side– at duodenitis, in the right iliac area – at
appendicitis, proximal colitis, in the left iliac area – at distal colitis, pathology of sigmoid colon.
Pain in all parts of abdomen is characteristic of enteritis, meteorism, and girdling pain – of
pancreatitis.
Character of a pain
Diffuse pain is observed in inflammatory processes of intestine, and liver. Localized pain is
characteristic of cholecystitis, gastric and duodenal ulcer. Dull pain arise at diseases of liver,
billiary dyskinesia, at colitis, gastroduodenitis. Acute pain is characteristic of cholecystitis,
especially calculous, intestinal colic, and of ulcer disease. Irradiation in the left hypochondrium
is characteristic of diseases of pancreas, irradiation of pain under scapula, in the right humerus –
of diseases of billiary tract.
Pains can be continual and periodic. In case of periodic pain it is necessary to pay attention to
their connection with food intake. Early pain arises first 30 minutes after meal, can be connected
with diseases of stomach, esophagus. Late pain – in 30 – 60 minutes after meal - is characteristic
of diseases of duodenum. Moininganoff’s rhythm of pain: night and hungry pain which remits
after food intake and renew in 30-40 minutes is characteristic of duodenal ulcer. Character of
nutrition also influences on occurrence of abdominal pain. Pain after spicy, fat, fried meal is
characteristic of billiary diseases. Pain after physical exertion is connected with diseases of
parenchymatous organs at stretching of their capsule – liver, pancreatic, spleen diseases.
The intensive periodic pain is conserned with intestinal peristalsis and accompanying with
allocation of bloody slime from a rectum on type of crimson jelly is characteristic of
invagination of intestine. After the ending of a peristaltic wave the child become quiet. The new
peristaltic wave associates with the beginning of new attack of pain.
Symptoms of gastric dyspepsia – eructation, heartburn, nausea, vomiting.
Eructation connects with infringement of gastrointestinal motility. More often the air eructation
observes. The ear eructation after meal in infants is connected with aerophagia and
underdevelopment of cardiac part of stomach and doesn’t have pathological value. The acidic
eructation is possible both at hyperacidity, and at hypoacidity ore normacidity. The acidic
eructation is connected with regurgitation of acidic contents of stomach to esophagus and mouth.
Foul-smelling eructation at children practically does not meet, since it’s never happen true
achylia.
Heartburn – feeling of burning behind the breastbone. The heartburn is caused by regurgitation
of acidic gastric contents to an esophagus and also does not always connected with hyperacidity.
The heartburn accompanies with a gastroesophageal reflux, esophagitis, diaphragmatic hernia,
cardioesophageal relaxation, chalasia.
The nausea arises at rising of intraduodenal pressure. It is peculiar to diseases of duodenum more
often, but can manifest the general intoxication at many infectious and parasitic diseases,
frequently precedes a vomiting.
The vomiting without nausea arises at brain injuries, meningocephalites, and rising of
intracranial pressure. The sudden vomiting is possible at irritation of vomit center at intoxication,
sea-sickness. Children with ketonemia frequently have uncontrollable vomiting with a smell of
acetone. At pathology of digestive system – gastritis, duodenitis, intestinal infections, food
poisonings the vomiting is always preceded with nausea. In children of the first year of life the
vomiting after feeding can be connected with pylorospasm or a pylorostenosis. In the first case
disease is functional. The vomiting arises from first days of life, but it is not plentiful and
observed not after each feeding, loss of body mass is insignificant. In the second case there is
congenital pathology of pylorus which demands surgical treatment. Disease manifests on 2-3
week of life. The fountain vomiting after each feeding is characteristic, and the quantity of vomit
mass can exceed quantity of the eaten food. Loss of body mass of has progressed. Visible
peristalsis is marked; sometimes on abdominal wall contour of "sand-glass" is present. The upper
part of this formation is overfull by food stomach; the lower part is overfull by gas intestine
owing to deficiency of nutrition. In 90 % pylorus is possible to palpate.
Regurgitation in infants is variant of norm. Unlike vomiting, regurgitation occurs without effort
and strain of muscles of prelum abdominale.
Symptoms of intestinal dyspepsia are diarrhea, constipation, meteorism and rumbling.
Diarrhea. At the simple dyspepsia which is connected with qualitative dietetic error in yang
children, the watery stool with admixture of green, undigested agglomerates of food is observed.
At toxic dyspepsia stool is watery, light yellow, with an impurity of slime.
Excrements at dysentery content impurity of slime, pus and blood. The defecation is
accompanied by tenesmus – morbid call to stool. At salmonellosis faeces have green color, with
impurity of slime. At cholera the white vomiting and white plentiful liquid stool, up to 100 times
per day are observed.
Polyfecalia in combination of presence of viscous stool is characteristic of malabsorbtion
syndrome. At chronic diseases of intestine – Crohn’s disease and a nonspecific ulcerative colitis
- excrements with impurity of blood and slime may observes. Abdominal pain, rapid watery
stool, especially at night, tenesmus are marked.
At bleeding in the upper parts of a gastrointestinal tract the patient has melena – black faeces. In
a case of bleeding from lower departments of large intestine – in excrements presents not
changed blood. At anal fissure the blood has scarlet color, and not mixes with faeces.
Constipation – delay of stool more than 48 hours. If the stool is absent since a birth within
several days, it is possible to think about congenital anomaly of an intestine – megacolon,
Hirschsprung’s disease, or about congenital hypothyroidism. In older children constipations can
be connected with dolyhosigma, dolyhocolon.
Meteorism and rumbling arise owing to infringement of an adsorption of gases and liquid
contents in a terminal department of an ileum and proximal departments of a large intestine.
They are observed at a pancreatitis, colitis, dysbacteriosis.
Poor appetite and anorexia can be displays of intoxication. Anorexia of a psychogenic
parentage, and also because of phobia of occurrence of pain is possible at gastroduodenitis, a
peptic ulcer, constipations. Appetite is reduced at helminthic invasions, hypovitaminoses C and
B, hypervitaminosis D.
Discoloration of a skin. Paleness, shadows under eyes can be displays of the general
intoxication. At diseases of gastrointestinal tract the jaundice can be observed. The jaundice can
be exogenous, connected with superfluous entering of Carotinum. In this case scleras are light,
and palms and soles are painted more brightly. Endogenic jaundice is connected with
infringement of bilirubin methabolism. The bilirubin is formed at destruction of a heme. It is
indirect, inconjugated, an insoluble bilirubin which does not pass through the renal filter. With
the help of albumin it is transported to liver where connect with glucuronic acid. Conjugated,
soluble bilirubin, which easy penetrate into urine, is formed. Conjugated bilirubin is excreted to
bile and to faeces as a stercobilin. The part of stercobilin is soaked up and excreted by kidneys as
an urobilinogen.
The hemolytic jaundice is observed at hemolytic disease of newborns, congenital hemolytic
anemia, some infectious diseases – malarias, leishmaniasis, influents of hemotoxins. A skin is
citreous color. The liver is expanded less, than spleen. Faeces have usual color. In urine there is
no bilirubin, but it is a lot of urobilin. Functional assays of a liver are not changed. The
erythrocyte osmotic resistance is reduced, the high reticulocytosis is marked. The indirect
bilirubin is increased.
Parenchymatous jaundice is characteristic of diseases of liver – hepatitis, cirrhosis.
The yellowness with a reddish shade is observed. Urine is dark because of bilirubin contained in
it. The faeces periodically decolorized. The liver enlarged, morbid. Functional biochemical
parameters of liver are increased. In a blood raises direct and indirect bilirubin.
The mechanical jaundice is caused by a obstruction of billiary tract. Skin has greenish shade. The
dermal itch is marked. The liver enlarged. The direct bilirubin is increased. Urine is dark,
contains bilirubin, the faeces are decolorized.
At survey pay attention to presence of the expanded dermal capillaries – stellate angioma,
hyperemia of palms – hepatic palms. It is the marks of liver diseases– hepatitis and cirrhosis. The
expressed abdominal venous network – head of a jellyfish – says about a portal hypertension.
The augmentation of abdomen in volume is observed at ascitis, meteorism, augmentation of a
liver and spleen, tumor, megacolon, Hirschsprung’s disease.
The retraction of abdominal wall and its strain is peculiar to peritonitis and other acute
abdominal diseases which require the urgent surgical help. The severe abdominal pain can be
accompanied by vomiting, delay of stool and gases, diarrhea, melena. A position of the child is
forced, on one side with pressing to abdomen legs. A look is suffering, features are pointed –
Hippocras face. There are signs of intoxication – paleness of a skin, rise temperature, a nausea,
vomiting. Positive Blumberg's sign, guarding symptom– intensifying of an abdominal pain is
observed at turning up of the doctor’s hand after pressing on abdominal wall.