Gastrointestinal function secretion regulation Daniel Hodyc Department of
- Slides: 35
Gastrointestinal function secretion, regulation Daniel Hodyc Department of Physiology Pictures and schemes – L. R. Johnson – Essential Medical Physiology, Elsevier, 2003
GIT secretion 1. Salivary secretion 2. Gastric secretion 3. Pancreatic secretion
Salivary secretion
Anatomy, Inervation
Functions of saliva Digestion - ptyalin (α-amylase) - identical to pancreatic amylase - cleaves α-1, 4 -glycosidic bonds of carbohydrates - 75 % of starch, p. H optimum 7 - functionally replaceable by pancreatic enzyme - lingual lipase - triglycerides - lower acidic optimum – remains active throughout the stomach and into the proximal duodenum - dissolves dietary constituents - increases the sensitivity of taste buds
Functions of saliva Lubrication - mucus content - facilitates swallowing - necessary for speech Protection - dilution and buffering of harmful substances - salivation before vomiting - xerostomia chronic infections - lysozym, Ig. A binding protein, lactoferin - take-up of Ca and phosphate - concentration
Composition of saliva Major characteristics of saliva: - relatively large volume - high potassium concentration - low osmolarity - two stages in secretion acini x salivary duct - specialized organic materials
Composition of saliva
Composition of saliva
Composition of saliva Organic composition: - ptyalin, lipase - lysozym, Ig. A binding protein, lactoferin kallikrein α-globulin bradykinin vasodilation
Neural regulation of secretion
Gastric secretion
Gastric secretion Gastric juice - hydrochloric acid - conversion of pepsinogen to pepsine - bacteriostatic effect - pepsin - protein digestion - replaceable by pancreatic enzymes - mucus - protective coating, lubricant - part of gastric mucosal barrier - intrinsic factor - binds B 12 vitamin, absorption in the ileum - the only indispensable substance in gastric juice
Gastric secretion Oxyntic gland Secretory regions
Gastric juice electrolytes
Hydrochloric acid secretion alkaline tide
Stimulation of acid secretion Potentiation of agents Parasympathetics (Ach) Gastrin Histamine
Hydrochloric acid secretion – perietal cell Nonsecreting cell Secreting cell
Stimulation of acid secretion – cephalic phase blocked by vagotomy sham feeding hypoglycemia role of GRP (bombesin)
Gastric phase 60 % of acid response distension peptides calcium alcohol caffeine
Stimulation of gastric acid secretion
Regulation of gastrin release Acetylcholine Gastrin Cell Somatostatin Cell
Intragastric p. H after a meal Stomach – somatostatin Duodenum – secretin, hyperosmotic chyme fatty acids Inhibition of acid secretion
Production of Pepsinogen Ach H+ Pepsin
Pancreatic secretion
Secretion of water and electrolytes Na, K – the same as in plasma Bicarbonate concentration – up to 5 times higher than in plasma
Mechanism of water and electrolytes secretion Na-K-ATPase Bicarbonate in plasma High extracellular Cl- concentration Carbonic anhydrase
Mechanism of enzymes secretion Proteolytic enzymes – secreted as inactive precursors chymotrypsinogen prokarboxypeptidase trypsinogen enterokinase trypsin chymotrypsin karboxypeptidase
Mechanism of enzymes secretion Inhibition of pancreatic autodigestion chymotrypsinogen prokarboxypeptidase trypsinogen enterokinase trypsin Trypsin inhibitor chymotrypsin karboxypeptidase
Mechanism of enzymes secretion Inhibition of pancreatic autodigestion chymotrypsinogen prokarboxypeptidase trypsinogen enterokinase trypsin Trypsin inhibitor Failure chymotrypsin karboxypeptidase PANCREATITIS
Mechanism of enzymes secretion Glycolytic enzymes - secreted as active enzymes - pancreatic α-amylase - cleaves starch and glycogen into di- and trisacharides Lypolytic enzymes - secreted as active enzymes - pancreatic lipase - glycerol + fatty acids
Regulation of pancreatic secretion Cephalic and gastric phase Acetylcholine CCK enzymes Secretin water bicarbonate
Regulation of pancreatic secretion Intestinal phase Acetylcholine CCK Fat enzymes H+ Secretin water bicarbonate
Response to a meal neutralization - pancreatic bicarbonate changes in diet changes in enzyme secretion
The effect of potentiation of enzyme secretion in pancreas Phenylalanin + Secretin (CCK) Secretin 1 unit / kg. hr Phenylalanin (CCK)
- Florida department of financial regulation
- Hines hill train collision
- Lara renew nursing license
- Embriologia del sistema gastrointestinal
- Gastrointestinal tract
- Chemotrypsinogen
- Emt chapter 18 gastrointestinal and urologic emergencies
- Chapter 15 the gastrointestinal system
- Gastrointestinal hormones
- Dr sigid djuniawan
- Docimasia gastrointestinal de breslau
- Endojen opiatlar
- Gastrointestinal medical terminology breakdown
- Nutrition focused physical findings
- Foregut
- Composition of stomach
- Motilidad gastrointestinal
- Upper gi bleeding management
- L
- Sistema digestorio
- Conistipation
- Gastrointestinal tüp aracılığıyla ilaç uygulama
- Gastrointestinal structure
- Peristalsis and segmentation
- Why does metformin cause gastrointestinal problems
- Alimentary canal
- Hirschsprung disease nursing management
- Nursing management of gastrointestinal disorders
- Renal plasma flow
- اعادة امتصاص الماء في الكلية
- Tubular secretion
- Thyroid hormone secretion
- Thyroid hormone secretion
- Msh secretion
- Where does secretion occur in nephron
- Enterokinase enzyme function