Pathophysiology of gastro-intestinal tract Gastro-intestinal tract

  • Размер: 2.7 Mегабайта
  • Количество слайдов: 24

Описание презентации Pathophysiology of gastro-intestinal tract Gastro-intestinal tract по слайдам

  Pathophysiology of gastro-intestinal tract Pathophysiology of gastro-intestinal tract

  Gastro-intestinal tract • Organs of oral cavity • Esophagus • Stomach • Small and Gastro-intestinal tract • Organs of oral cavity • Esophagus • Stomach • Small and large intestine • Secretory function of salivary glands, liver, pancreas Neurohormonal regulation

  Major processes in GIT nutrition digestion ,  absorption movement. Salivary glands absorption Vena Major processes in GIT nutrition digestion , absorption movement. Salivary glands absorption Vena cava rectumstomach esophagus Colonintestine secretiondigestion motility

  Physiology of the stomach пищевод дно Pyloric sphincterдвенадцатиперстная кишка антральный отдел (секреция слизи, Physiology of the stomach пищевод дно Pyloric sphincterдвенадцатиперстная кишка антральный отдел (секреция слизи, пепсиногена, гастрина) isthmus Parietal cells Smooth muscle cells G-cells. Chief cells тело (секреция слизи, пепсиногена, HCl)

  Antral G-cell Parietal cell Gastrin Н + secretion К + , H + АТФ Antral G-cell Parietal cell Gastrin Н + secretion К + , H + АТФ ase CNS Acetylcholine Antral receptor Local reflex Histamine Acetylcholine Stretch Parietal receptor Food (view, smell, test )Regulation of gastric secretion

  Mechanisms of gastric hypersecretion  • Stimulation :   neurogenic (vagotonia) , Mechanisms of gastric hypersecretion • Stimulation : neurogenic (vagotonia) , hormonal ( gastrin, histamine, ↑Ca 2+ in hyperparathyroidism …) • Failure of inhibitory mechanisms ( antral , duodenal ) • Hyperplasia of the gastric glands

  Gastrinoma (Zollinger-Ellison syndrome) • Marked gastric hypersecretion • Diarrhea • Abdominal pain • Peptic Gastrinoma (Zollinger-Ellison syndrome) • Marked gastric hypersecretion • Diarrhea • Abdominal pain • Peptic ulcer(s) of upper GI tract • Gastro-esophageal reflux • Gastrin-secreting tumor of the duodenum (75%), pancreas (24%), stomach, liver, ovary (1%).

  Pathogenic consequences of gastric hypersecretion • Disorders of gastric motility (hypercontraction) • Disorders of Pathogenic consequences of gastric hypersecretion • Disorders of gastric motility (hypercontraction) • Disorders of digestion • Hyperkinesia • Disorders of water-electrolyte and acid-base balance Development of acid-dependent diseases Erosion Acute ulcer Chronic ulcer mucosa Submucous layer Muscle layer Serous

  mucus bicarbonate PG Е 2 Adequate blood flow HCl pepsin Bile acids Helicobacter р mucus bicarbonate PG Е 2 Adequate blood flow HCl pepsin Bile acids Helicobacter р yloriagressive. Aggressive and protective factors of gastric juice amylinprotective

  Helicobacter pylori Helicobacter pylori

  The role of  Helicobacter  pylori  Helicobacter pylori urease urea ammonia Increase The role of Helicobacter pylori Helicobacter pylori urease urea ammonia Increase of p. H in antrum Gastrin production Hyperproduction of НС l Increase of IFN , TNF apoptosis , slowing of regeneration and reparation Antral gastritis B , ulcer Risk of cancer Cytiotoxic effect cytotoxines ( Vac A, Cag A…) Injury of epithelium Infiltration with neutrophils

  Ulceroprotective effect of amylin • Inhibition of gastric secretion • Stimulation of production of Ulceroprotective effect of amylin • Inhibition of gastric secretion • Stimulation of production of mucus • Acceleration of healing of mucosa C N H 23 7 a m i n o a c i d p o l y p e p t i d e

  Pathogenesis of gastro-esophageal reflux disease (GERD) Motor dysfunction of the lower esophageal sphincter Gastro-esophageal Pathogenesis of gastro-esophageal reflux disease (GERD) Motor dysfunction of the lower esophageal sphincter Gastro-esophageal reflux. Decreased mucosal resistance Increase in intragastric pressure Decreased esophageal clearance Gravity Esophageal peristaltics. Saliva Renewal of the epithelium

  Mechanisms of gastric hyposecretion • Disorders of regulation ( neurogenic ,  hormonal ) Mechanisms of gastric hyposecretion • Disorders of regulation ( neurogenic , hormonal ) • Atrophy of mucosa (autoimmune gastritis) • Resection of the stomach

  Induction of autoimunity against parietal cells Induction of autoimunity against parietal cells

  Mechanisms of immune-mediated parietal cell death leading to gastric atrophy Mechanisms of immune-mediated parietal cell death leading to gastric atrophy

  Complications of gastric hyposecretion • Disorders of protein digestion • Hypokinesia • Disorders in Complications of gastric hyposecretion • Disorders of protein digestion • Hypokinesia • Disorders in barrier function • Disorders of iron and vitamin В 12 absorption • Disorders of intestinal secretion and digestion

  Increased gastric motility (gastric hyperkinesia) • Neurogenic • Increased production of НС l , Increased gastric motility (gastric hyperkinesia) • Neurogenic • Increased production of НС l , gastrin , motilin … • Hypercalcemia • Pylorostenosis Complications : • Decrease volume adaptation • Increase in intragastric pressure • Increased tone of the stomach • Dyspepsia

  Decrease of gastric motility • Neurogenic   - reflex gastroparesis   - Decrease of gastric motility • Neurogenic — reflex gastroparesis — authonomic neuropathy (diabetes, alcoholism) — vagotomia • Humoral — hyposecretion of Н CL — increased production of HCl , GIP , amylin … • Disorders of smooth muscle cell metabolism — anorexia — chronic intoxication — hypokalemia — ischemia

  The passage of chyme through GI tract in normal conditions (A) and after resection The passage of chyme through GI tract in normal conditions (A) and after resection of stomach (B)

  The consequences of stomach resection • Disorders in reservoir function of the stomach • The consequences of stomach resection • Disorders in reservoir function of the stomach • Decreased number of secretory cells ( achlorhydria) • Vitamin B 12 deficiency → anemia • Disturbance of fractional influx of chyme into the duodenum • Disturbances in the regulation of secretory function of pancreas and liver • Accelerated passage of chyme through the small intestine

  Mechanisms of jejunal (postgastrectomy,  dumping) syndrome Early ( ~75 ) Dumping of the Mechanisms of jejunal (postgastrectomy, dumping) syndrome Early ( ~75% ) Dumping of the hyperosmolar chyme into the intestine • Influx of water into the lumen • Stimulation of intestinal peristaltics • Stimulation of BAS formation ( 5 -HT, VIP, kinins etc. ) Late ( ~25% ) Absorption of high amount of carbohydrates into the blood • Hyperglycemia insulin release hypoglycemia activation of sympathetic nervous system tachycardia, perspiration