Gastrointestinal physiology II
Stomach
- Overview of functions (storage, digestion, chyme regulation + intrinsic factor)
- Role of the chief and parietal cells - Gastric secretion patterns
- The crucial role of the proton (H-K-ATPase) pump in hydrogen ion management
- Protective mucosal barrier mechanisms within the gastric lumen
- Secretion patterns (cephalic, gastric, intestinal) and their stimulant pathways
- Chyme production and its effects upon the pyloric sphincter
- Factors affecting gastric emptying (duodenal luminal pH, fats, distension)
Small intestine
- Duodenally-mediated inhibition of gastric juice release and its hormonal components
- Effects of addition of water, bicarbonate and bile upon duodenal chyme
- Functional anatomy of the intestinal villus
- Importance of the sodium pump in creating the osmotic gradient of the small intestine
- Carbohydrate handling in the gut (brush border enzymes, cotransporters, diffusion)
- Functional effects of proteases and carboxypeptidase - Protein digestion
- Calcium absorption via Ca-ATPase and Na-Ca antiporter mechanisms - Calcium handling in small intestine
- Iron absorption via ascorbate complexes and carrier proteins - Iron handling in the gut
- Fat handling (emulsification agents, micelles) and the handling of fat-soluble vitamins
Pancreas
- Principal constituents of the exocrine pancreatic juice = exocrine pancreas
- Function and origin of CCK
- Function and origin of secretin
Liver
- Constituents of a portal triad
- Origin and constituents of hepatic bile - see bile salts
- Pathway of enterohepatic circulation - see Bilirubin metabolism
- Appreciation of both its storage and metabolic roles (bile concentration region)
- Stimulants to bile formation (bile salts, secretin, glucagons, gastrin → Gastric secretion patterns)
- Role of CCK and vagal stimulation in bile release
Large intestine
- Factors affecting opening of the ileocaecal sphincter
- Functional role of the taeniae coli via autonomic innervation
- Handling of chyme as being a combination of mixing + propulsion
- Role of Na-K-ATPase in water absorption against a concentration gradient (Water reabsorption from chyme)
- Overview of the role of colonic bacteria (vitamin synthesis, bile + Bilirubin handling)
- Functional basis of colonic mass movement (based upon mid-zone GI distension)
- Basis of the Defaecation reflex