pathophysiology of digestion md, prof. yu.i. bondarenko

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Pathophysiolo gy of digestion MD, Prof. Yu.I. Bondarenko

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Page 1: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

Pathophysiology

of digestion

MD, Prof. Yu.I. Bondarenko

Page 2: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

INSUFFICIENCY OF DIGESTION. THE REASONS. MANIFESTATIONS

The basic role of digestive system consists in digestion of components of food that enter into an alimentary canal (proteins, fats, carbohydrates), absorption of formed nutrients and removing from an organism end-products of metabolism.

Numerous functions of digestive system are regulated by the central and autonomic nervous system, humoral and endocrine influences.

Disorders of regulation cause disturbance of normal course of the processes in an alimentary canal, result in insufficiency of digestion and promote development of many diseases.

Page 3: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

INSUFFICIENCY OF DIGESTION

It is pathological condition at which the digestive system does not provide assimilation of the nutrients that enter in the organism. hereditary insufficiency of digestion (some kinds malabsorption)acquired insufficiency of digestion

Page 4: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

CAUSES OF DIGESTION INSUFFICIENCY DEVELOPMENT 1. Alimentary (food) factors:

a) reception of bad and rough food b) dry rations c) irregular reception of food d) disbalanced meal (for example, reduction

of the contain of vitamins, proteins in diet)

e) abuse in alcohol2. Physical factors Greatest role belonge to radiation which

damage epithelial cells of the alimentary channel which have high mitotic activity

Page 5: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

3. Chemical agents: Poisonings with inorganic and organic compounds.

4. Biological factors: a) bacterium (for example, v.cholera,

dysentery, typhoid, paratyphoid fever) b) bacterial toxins (for example,

salmonellosis, staphylococcus infection) c) viruses (for example, adenoviruses) d) helminths5. Organic effects: a) congenital anomalies of digestive

system b) postoperative conditions c) tumors of digestive system

Page 6: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

6. Disorders of nervous and humoral regulation:

a) psychoemotional disorders (neurotic and neurosis-like conditions)

b) mental diseases (schizophrenia, maniac - depressive syndrome)

c) organic diseases of the central nervous system (encephalites)

d) lesions of peripheral structures of autonomal nervous system

e) reflex disorder (various viscero-visceral reflexes)

Disorders of humoral regulation of digestion may be connected to disorders of synthesis and secretion gastrointestinal hormones (gastrine, secretin, cholecystokinin-pancreazymin etc.)

Page 7: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

INSUFFICIENCY OF DIGESTION MAY MANIFESTS SYNDROMES:

1. Starvation2. Dispeptic syndrome3. Dehydratation4. Disturbance of the acid-

base balance5. Intestinal autointoxication6. Painful syndrome

Page 8: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

DISPEPTIC SYNDROMEDispeptic syndrome includes different combinations of the

following symptoms:

a) anorexia

b) heartburn

c) eructation

d) nausea

e) vomitting

f) meteorism

g) constipations

h) diarrhea

Page 9: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

ANOREXIA Anorexia is a full absence of appetite while

person need food

Kinds of the anorexia:

а) intoxical - develops during acute and chronic poisonings (for example, salts of mercury, medical products, bacterial toxins)

b) dispeptic - arises at diseases of digestive system, has more often behavior-reflex nature

c) neurodynamic - develops as a result reciprocal disturbance of the appetite centre after overexcitation of structures limbic systems (for example, painful syndrome during heart attacks, colics, peritonitis)

Page 10: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

ANOREXIAd) neurotic - is connected with

excessive excitation of cortex brain and strong emotions (especialy negative)

e) psychogenic – is connected with conscious restriction of food (for example, with an aim of getting thin or as result of mental disorders)

f) neuroendocrinopathy - is caused by organic lesion of the central nervous system (hypothalamus) and endocrine diseases (hypophysial cachexia, Addison’s disease)

Page 11: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

MECHANISMS OF ANOREXIA DEVELOPMENT :

1. Reduction of excitability of the food centre (intoxical, dispeptic, neuroendocrinopathy anorexia)

2. Inhibition of neurons of the food centre (neurodynamic, neurotic, psychogenic anorexia)

Page 12: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

The heartburn is a feeling of heat or burnings long esophagus.

Development is connected with irritation of receptors of esophagus during pelting contents of stomach into one (reflux).

It may be caused by:а) increase forming of gastric juiceb) functional insufficiency of cardial

sphincter

Page 13: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

The eructation is sudden involuntary allocation into oral cavity some gas from a stomach or a gullet, sometimes with small portions of contents of a stomach

The increasing of the contents of gases in stomach may be caused by two reasons:

а) receipt big quantity of gases with food and a drink (for example, aerated drinks), siping of air (aerofagia)

b) formation of gases in the stomach, it is especial at a long delay there peep (at a stomach ulcer, cancer of a stomach)

As a result of increasing of the contents of gases in a stomach it is increased intrastomach pressure. It reflexly can cause:

а) reduction of muscles of a stomach wall b) a spasm of the gatekeeper c) a relaxation of muscles of aesophagal-gastric

sphincterThereof gases are superseded from a cavity of a

stomach in a gullet, to a drink. And then in an oral cavity

Page 14: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

The nausea is a burdensome sensation in epigastric area breast and in the oral cavities, quite often previous to vomitting and frequently accompanying with the general weakness, sweatness, increasing of salivation, coldness of arms and legs, pallor of a skin, decrease of arterial pressure that is connected to activation parasympathic nervous system. In a basis of a nausea is an excitation of the emetic centre, but insufficient for occurrence of vomitting lays.

Vomitting - the complex-reflex act which results to eruption of contents of a stomach outside through a mouth is a result of excitation of the emetic centre which is situated in an oblong brain.

Page 15: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

The mechanism of vomitting includes a number of consecutive stages. His pick out the following pathogenetic variants of vomitting:

а) central - it is connected with increasing of excitability of the emetic centre. It happens at diseases of the central nervous system (meningitises, encephalities, tumours of a brain), at excitation of cortex of the big hemispheres (behavior-reflex vomitting) or receptors of a labyrinth (vestibular vomitting);

b) hematogenic-toxic - it is caused by direct action of toxic substances which are in blood, on receptors that are in emetic centre. It may be exogenous substances (carbonic oxide, alcohol, medical products, toxins of bacteria) or toxic products of an own metabolism which are collected during at a uremia, hepatic insufficiency, decompensated diabetes and others;

c) visceral (reflex) – is a result of reflexes which are caused from different receptors of internal organs. Such reflexogenic zones are in a stomach, a mucous membrane of pharynx, coronal vessels, peritoneum, biliary duct etc.

Page 16: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

Meteorism is a superfluous accumulation of gases in the digestive channel due to their increased formation or insufficient removing from intestines

Superfluous formation of gases underlies development of the following kinds of meteorism:

а) alimentary - develops at reception with food a lot cellulose, starches (leguminous, cabbage, a potato)

b) disorders of digestion (pathology of enzymes, disturbances of absorbtion, intestinal disbacterioses)

Page 17: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

Disturbance of discharge of gases typically for such meteorism:

а) mechanical - develops as a result of Disturbance of passableness of intestines (spasms, solderings, tumours)

b) dynamic - arises at disorders of motor function of intestines

c) circular – is a result of the general and local disorders of blood circulation

Page 18: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

It is pick out two mechanisms of development of constipations - spastic and atonic.

The first is caused by long constant reduction of smooth muscles of guts, the second – because of their atonia.

To spastic constipations concern:а) inflammatory - arise owing to local

spastic reflexes with changed of mucous membrane;

b) proctogenic - develop at a pathology anorectal areas;

c) mechanical - arise at impassability of guts;

d) toxic – is result of poisonings lead, mercury, thallium.

Page 19: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

Atonic constipations are:

а) alimentary - develop at receipt light food containing(not enough) cellulose

b) neurogenic – is the result of disorders of nervous regulation of a motility of guts

c) hypodynamic - arise at bed patients, at old men, people with very low motor activity

d) constipations at anomalies of a thick gut (Girshprungs disease)

e) constipations in consequensce disorders water-electrolyte metabolism

Page 20: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

Diarrhea Pathogenetic variants of diarrheas:а) osmotic diarrhea. Develops when osmotic

pressure is increase because of intestinal contents at intake of substances which are bad or are not absorbed at all (for example, laxative), and also at disturbances of digestion and absorbtion (syndromes maldigestion and malabsorbtion)

b) secretory diarrhea. It is connected with activation of secretion of ions (Na+ , Cl‾), that causes the strengthened secretion of water into gap of guts (for example, during cholera)

c) diarrhea, caused by braking of active transport of ions through cellular membranes in guts (for example, congenital chlordiarrhea - genetic defect of absorbtion of anions of chlorine in illeum)

d) diarrhea is caused by increase of permeability of an intestinal wall (inflammatory)

e) diarrhea at disturbance of an intestinal motility

Page 21: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

Intestinal autointoxication, as a rule, is connected with infringement corelation between bacterias and formation a plenty of toxic products of fermentation and putrafaction.

Dysbacteriosis is an infringement of a ratio between separate kinds of microflora. Thus the quantity of the bacteria causing processes of putrafaction and fermentation is frequently increased. As a result formation in guts of toxic products - hydrogen sulphide, scatol, indole, phenols, putrescine, cadaverine grows etc. If formation of these products exceeds functional ability of a liver on them detoxifcation, attributes of hepatic insufficiency develop. Development of intestinal autointoxication is promoted by reduction of intestinal peristalsis(constipations), reduction of secretion of intestinal juice, intestinal obstruction.

Page 22: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

PAINThe pain frequently accompanies with

development of diseases of the alimentary channel. Depending to the reasons and pathogenesis pain may have different characters.

Distinguish the following mechanisms of occurrence of pain at lesions of digestive organs:

The spastic mechanism. The pain is caused by a spasm of smooth muscles of different parts of the alimentary channel. In this case the reason of pain is constriction of the vessels which are located in the wall of hollow organs owing to that the ischemia develops. It cause appearance of metabolism products in the working organs, and their influence on pain receptors. At sharply arising strong spasm pain on colics type develops

Page 23: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

PAINThe hypotonic mechanism. At reduction of

smooth muscles tone (hypotonia) the pain appears due to stretching the wall of hollow organs ( stomach, guts, gall bladder) by their contents. Thus the mechanical stretching of tissues causes irritation of the nervous endings;

Influence of biological active substances (histamine, serotonin, kinines, prostaglandins) on the nervous endings. These substances are formed and secreted at damage of cells and inflammation (gastritis, duodenitis, enteritis, colitis, cholecystitis). Especially a lot of these substances appear during acute pancreatitis.

Page 24: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

FUNCTIONAL DISORDERS OF DIGESTIVE SYSTEM 1. Disturbance of digestive system

secretion :а) hypersecretion states: 1 hypersalivation 2 gastric hypersecretion 3 pancreatic hypersecretion 4 hypercholiab) hyposecretion states: 1 hyposalivation 2 gastric hyposecretion 3 pancreatic hyposecretion 4 acholia

Page 25: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

2. Disturbance of motor function of the alimentary channel:

1 disturbance of chewing

2 disturbances of swallowing - dysphagia

3 gastric dyskinesia

4 intestinal dyskinesia

5 dyskinesia of gall bladder and biliary ducts

6 disturbances of defecation

3. Disturbance of digestive and absorptive functions - syndromes of maldigestion and malabsorption.

Page 26: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

HYDROCHLORIC ACID, PEPSIN, MUCUS SECRETION DISTURBANCE

Hydrochloric acid is secreted with parietal cells of mucous membrane of stomach. Their number in the healthy person is about 1 billion.

Phases of secretion: 1.Neurogenic (vagal); 2.Gastric (gastrine); 3.Intestinal that is regulated by intestinal

hormones.In regulation of functional activity of parietal cells

takes place nervous system (through mediator acethylcholine), and also various hormones (serotonin, insulin). The parietal cell contains receptors to histamine which is released from enterochromaphilic cells (ECL), gastrin and cholecystokinin (CCK-receptors), and also receptors for acethylcholine (M3-receptors),

Page 27: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

REGULATION OF OUTPUT HCLStimulation of H2-histamine receptors is bring on

formation cAMP, and stimulation of CCK-receptors and M3-receptors results to increasing of level of endocellular calcium (Са++).

Stimulation of M3-receptors increases, not only total Са++ into cell and due to increasing of level inositolthreephosphate (IP3) strengthens an output of endocellular Са++.

Gastrin, cholecystokinin and histamine also raise output of Са++ due to action on IPh3 .

Parietal cell has receptor to prostaglandin E2 (PGE2)) which stimulation reduces level cAMP and results ihibition of hydrochloric acid secretion.

Secretion of hydrochloric acid by parietal cell is carried out by principle of the proton pump in which K+ exchanges on H+, and Cl-‾ on HCO3-‾. An important role in this process plays H+, K+ -ATPase which, using energy of ATP, provides transport H+ from parietal cells and K+ into cell.

Page 28: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko
Page 29: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko
Page 30: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

Hypersecretion of hydrochloric acid plays the important role in development of several gastroenterologic illness, may be observed at hereditary conditioned increasing of weight parietal cells, the increased tone of a vagal nerve, stretching of antral part of stomach during disorder of emptying, increasing of secretion of gastrin, increasing quantity of ECL-cells in the mucous membrane of stomach (in the patients with carcinoid syndrome).

The main cells of mucous membrane form pepsin . It is know seven types of pepsinogen. Disturbance of pepsin formation take place in the number gastroenterologic diseases (for example, stomach ulcer).

Page 31: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

Gastric mucus is secreted by stomach mucous cells. Into structure of gastric musous contain glycosaminoglycans and glycoproteins.

From sialic acids N-acethylneuraminic acid provides ability of gastric mucus to form water-insoluble viscose lay of stomach mucus membrane.

Stimulating influence on formation of mucus result irritation of adreno- and cholinoreceptors, prostaglandins. Hydrolysis of lisosoms cause dehydratation of glycoproteins.

Gastric mucus (together with bicarbonates) takes part in formation of mucus barrier which supports a gradient рН between hollow of stomach and its mucus membrane and H+.

Disturbance of this barrier as a result of reduction the synthesis of prostaglandins in the wall of stomach.

Page 32: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

GASTRIC HYPERSECRETION IS CHARACTERIZED :

Increased quantity of gastric juice as after reception of food and also on the empty stomach

Hyperaciditas and hyperchlorhydria - is increase of the common acidity and the maintenance of free hydrochloric acid of gastric juice

Increasing of digestive ability of gastric juice

Page 33: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

The disturbances of digestion connected with gastric hypersecretion, are caused with long delay food in the stomach (pylorus is closed, because neutralization of very acidic contents that goes into duodenum,it take a lot time).

Consequences: A little contents that enter into guts lead to

reduction of gut peristaltic and constipation development.

Processes of fermentation and formation gases is amplified in the stomach. It causes appearance of eructation and heartburn

Motor activity of stomach is increased as a result hypertone and hyperkinesis of smooth muscles.

Page 34: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

GASTRIC HYPOSECRETION IS CHARACTERIZED:Reduction the quantity of gastric juice

on an empty stomach and after reception of food

Decreased or zero acidity of gastric juice (hypo-or unacidity), reduction of the contents in it or absence of the free hydrochloric acid (hypo- or achlorhydria)

Reduction of digesting ability of gastric juice due to achylia (the full stop formation a hydrochloric acid and enzymes)

Page 35: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

Reduction of gastric secretion stipulated disturbance of digestion along alimentary channel.

Insufficient formation of gastric juice that keeps pylorus opened also contents of stomach quickly passes into duodenum where environment becomes constantly alkaline. It causes inhibition of formation secretin.

Insufficiently digested components of food irritate receptors of mucus membrane of guts that results in their strengthening of peristaltic and diarrhea develop.

Besides an absence of a hydrochloric acid leads to development of microflora in the stomach.

Activation of processes of rotting and fermentation is connected appearance such disturbance of digestion, as an eructation, the impose tongue etc.

Page 36: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

DISTURBANCE OF STOMACH MOTOR FUNCTION Disturbance of stomach motor

function is called gastric diskinesia

Trere are two kinds of gastric diskinesia: hypertonic and hypotonic

Hypertonic kind is characterized strengthening of peristaltic(hyperkinesia) and increasing of stomach muscles tone (hypertonia)

The hypotonic kind, on the contrary, is characterized hypotonia and hypokinesia

Page 37: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

THE REASONS OF MOTOR GASTRIC DISTURBANCE OF HYPERTONIC

TYPE Some food factors (rough food, alcohol)Increase of gastric secretionIncrease of vagal nerve toneSome gastrointestinal hormones (motilin) Hypertension and hyperkinesia of stomach

leads to:A long time delay of food in stomach that

promotes increase of gastric secretion and development of ulcers of mucus membrane

Development antiperistaltic of stomach that results in development of dispeptic disturbances (an eructation, nausea, vomitting)

Page 38: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

One forms of diskinesia of stomach hypertonic type is pylorospasm

It is observed mainly in babies, especially in the first weeks and months of life.

Pylorospasm in children is caused by functional disturbances of the nervous- muscular system of pylorus part stomach. It is observed mainly at the excitable children who have transferred intra-uterine hypoxia, born in asphyxia with attributes of a birth trauma of the central nervous system

At pylorospasmis marked weak development of muscles in cardial parts of stomach and its more expressed development in the area of pylorus. It promotes development of vomitting and eructation

Page 39: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

CAUSES OF STOMACH MOTOR ACTIVITY REDUCTION Alimentary factors (fat food)Reduction of gastric secretion (hypoacidic

gastritis)Reduction of vagal nerve toneAction gastrointerstitial hormones

(gastroinhibiting peptide, secretine etc.)Removal of stomach pylorus The common weakening of organism, an

exhaustion, gastroptosis At hypotonic diskinesia time of staying of

food in the stomach is shortened that lead to disturbance of its digestion. Action undigested components of food on receptors of mucus membrane of guts causes increase of peristaltic and diarrhea.

Page 40: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

ETIOLOGY OF GASTRIC ULCER

Etiology of ulcer disease now is not established !

In development of stomach and duodenal ulcers take place the following risk factors1. Psychoemotional negative overstrains (negative emotions, conflict situations, feeling of constant alarm, overfatigue etc.)2. Stress3. Hereditary predisposition 4. Nutritional disorder – live on dry ration, irregular reception of nutriment, eating of rough or pungent food, bad chawing of food, fast meal, absence of the teeth, the insufficient contents in food of proteins and vitamins5. Chronic gastritis and duodenitis with increased secretion 6.The microbic factor - Helicobacter pylori7. Harmful habits - smoking, abuse of alcohol

Page 41: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

Pathogenesis of stomach ulcer in general is reduced to disturbance of balance between factors acid-peptic aggressions of gastric contents and elements of protection of stomach mucus membrane and duodenum.

Sufficient of bicarbonates buffer, good regeneration of epithelial cells, blood supply of mucus membrane, normal formation of prostaglandins in wall of stomach are factors that protect mucus.

Helicobacter pylori. These bacterias produce a lot of enzymes (urease, protease, phospholipase), damaging protective barrier of mucus membrane, and also various cytotoxins. The most pathogenic are Vac A-strains, that produce vacuolizing cytotoxin which results in formation cytoplasmatic vacuoles and destructions of epithelial cells, and the Sad A-strains which express gene associated with cytotoxin. This gene codes protein which has direct damaging effect on mucus membrane.

Helicobacter pylori promotes liberation in a mucus membrane of stomach interleukines, lisosomal enzymes, TNFα, that causes development of inflammatory processes in mucus.

Page 42: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

STOMACH PEPTIC ULCER

Page 43: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

PEPTIC STOMACH ULCER

Page 44: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

STOMACH AND DUODENUM ULCER

Page 45: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

HYSTOLOGY OF THE STOMACH ULCER

Page 46: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

DUODENUM ULCERS

Page 47: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

ACUTE STOMACH ULCERS

Page 48: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

DUODENUM ULCER

Page 49: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

INFECTIOUSES AGENTS OF STOMACH

Page 50: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

HELICOBACTER PYLORI

Page 51: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

DUODENUM ULCER

Page 52: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko
Page 53: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

Contamination of stomach mucus membrane by Helicobacter is accompanied by development superficial anthral gastritis and duodenitis and lead to increase level of gastrin with the subsequent increasing of hydrochloric acid secretion.

Excess of hydrochloric acid, getting into lumen of duodenum, in conditions of deficiency of pancreatic bicarbonates promotes development of duodenitis (remodulation of epithelium of duodenal mucus membrane on gastric type) which are quickly contaminated by Helicobacter.

Further at adverse current, especially when there are additional etiological factors (hereditary predisposition, 0 (1) group of blood, smoking, psychological an overstrain etc.), in area of metaplased mucus membrane ulcer defect is formed.

However connection of occurrence of stomach ulcer with infection of mucus membrane of stomach by Helicobacter revealed not always. Approximately 5 % of patients with ulcers of duodenum and of 15-20 % patients with stomach ulcers, disease develops without participation of these microorganisms.

Page 54: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

DISTURBANCE OF INTESTINAL FUNCTIONS

Functions of intestines may be disordered owing to many organic diseases. In some cases these disturbances arise owing to disturbances of nervous regulation of small and large intestine motility

Disturbance of digestion and absorbtion in intestines

The complex of disturbances which occur in an organism as a result of disturbance of digestion and absorbtion processes, received the name of a syndrome maldigestion and malabsorption

Page 55: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

THE SYNDROME MALDIGESTION

The syndrome of maldigestion is disturbances of primary digestion, caused by insufficient secretion into guts the digestive enzymes, in particular at pancreatic hyposecretion.

This syndrome is characterized:disturbance of digestion of fats (absence of lipase

and phospholipase). About 60-80 % of fat that get into guts is removed with feces – steatorrhea (fat in feces)

disturbance of absorption of fat-soluble vitamins – cause the development hypovitaminosis A,D, E and K

disturbance of digestion of proteins (absence of digestive proteases). About 30-40 % of food protein are not adopted. In feces there is plenty of muscular fibres

disturbance of digestion of carbohydrates (absence of amylase)

disturbance of nucleinic acids digestion (absence of nucleases)

Page 56: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

THE SYNDROME OF MALABSORPTION

It is complex of symptoms which occur in a result of disturbance absorption of substances in guts. Disturbance of absorbtion in guts may be caused by the disturbances that occur at three levels:

Preenterocytic disturbance. Develop as a result of disturbances of processes of digestion before absorbtion;

Enterocytic. Disturbance of activity epithelial cells of intestinal mucus membrane;

Postenterocytic. Disturbance of the processes that provides utilization of absorbed substances into internal environment of an organism (blood, lymph).

Page 57: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

PREENTEROCYTIC DISTURBANCES:

Disturbances of primary digestion (the syndrome maldigestion). By origin they may be gastrogenic, pancreatogenic, hepatogenic, enterogenic, disregulated, iatrogenic (connected with long usage of antibiotics and other medical drugs)

Disturbance of memrane digestion. More often it is caused by disturbance of formation and fixation of enzymes in plasmatic membrane of enterocytic microvillus

Interstitinal enzymopathies- hereditary caused disturbances of digestive enzymes synthesis by microvillus which provide processes of membrane digestion. Among interstitial pathology of enzymes the most often is intolerance to disaccharides (lactoses, saccharoses, tregaloses) and insufficiency of peptidase (gluten enteropathy, celiac disease).

Page 58: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

THE REASONS OF MALABSORBTION MAY BE SUCH ENTEROCYTIC DISTURBANCES:Reduction of absorption area ( condition after

resection of gut, an atrophy of villus and microvillus)

Hereditary and acquired disturbance of proteins formation - carriers monosaccharides (intolerance of glucose, galactose, fructoses), amino acids (tryptophanmalabsorbtion), ions calcium (hypovitaminosis D)

Disturbances of functioning ions pumps of enterocytes (transport monosaccharides and amino acids is connected with work of Na-K-pump)

Deficiency of energy (absorbtion the majority of substances - process energydependent)

Disturbance of formation in enterocytes of transport complexes (chilomicrones, lipoproteids)

Page 59: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

THE REASONS OF POSTENTEROCYTIC DISTURBANCES OF MALABSORPTION :

Disturbances of blood circulation in a wall of guts, may be caused with disturbances of general hemodynamic (ischemia, venous hyperemia, thrombosis, embolism, reaction of vessels in an inflammation);

Disturbances of lymph flow. Lymph circulation disorders may be connected to disturbances of constriction of intestinal wall fibres due to local reflex and act of villikinin.

Page 60: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

DISTURBANCES OF MOTOR FUNCTION OF INTESTINES

Disturbances of motor function of guts is called intestinal diskinesia.

There are two types of intestinal diskinesia: hyperkinetic and hypokinetic.

The first type is characterised strengthening of the peristalties, segmentary and pendulum-like movements. It manifastates by diarrhea.

The second, on the contrary, is characterized weakeing of motor activity of guts as a result constipations appears.

Page 61: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

THE REASONS OF INTESTINAL DISKINESIAS OF HYPERKINETIC TYPE:

Increasing excitability of receptors of guts to adequate irritators, that accompanies with development of an inflammation of an intestine mucus membrane (enteritis, colics)

Action on receptors of guts unusual, pathological irritators - undigested food (for example, achylia), products of rotting and fermentation, toxic substances etc.

Increasing of excitability of the vagal nerve centres Increase of some gastrointerstitial hormones form

that strengthening peristaltics of guts (motilin) Consequences intestinal diskinesias of

hyperkinetic type : Disturbances of digestion (digestion, absorbtion)Dehydratation Development of ungas acidosis (loss of

hydrocarbonates)

Page 62: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

INTESTINAL DYSKINESIA OF HYPERKINETIC TYPE It is manifestated with reduction of guts peristaltics. That results in appearance of constipations. In mechanisms of development it pick out two kinds of constipations: spastic and atonic.

Spastic constipations arise due to long time tonic reduction of smooth muscles constriction of guts (spasm) and may be caused by viscero-visceral reflexes, or action of toxic factors (for example, lead poisoning).

Reason of development atonic constipations connected with reduction of contractive function of smooth muscles guts:

a poor feed, the low contents of cellulose in nutritient.

Page 63: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

•excessive digestion of food into stomach (for example, gastric hypersecretion)

•age changes of receptor system of guts in old men, and also structural changes of an intestinal wall in obesity

•decrease of tone vagal nerve

•disturbances intraintestinal innervation, for example, Girshprungs disease - absence of ganglion cells Auerbachs plexus in sigmoideum and rectum

Page 64: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko

CONSEQUENCES OF THE INTESTINAL DYSKINESIA

Intestinal dyskinesia of hypokinetic type lead to: development of intestinal autointoxication occurrence meteorism formation of feces stones in extreme cases intestinal obstruction may

develop

Page 65: Pathophysiology of digestion MD, Prof. Yu.I. Bondarenko