Digestion (28-51) Flashcards
Absorption
Transport of the digested nutrients from the lumen of the intestine to the blood vessels across the intestinal wall.
Amylases
Enzymes that digest carbohydrates (in the saliva or pancreatic juice)
Cardiac sphincter
A ring of muscles separating the esophagus from the stomach.
CCK
Cholecystokinin. It is produces in the small intestine, and induces emptying of the gallbladder, increases enzyme production in the pancreas and inhibits emptying of the stomach.
Chief cells
Pepsinogen producing cells in the stomach.
Digestion
Chemical break-down og the nutritive macromolecules polymers (proteins, carbohydrates, lipids, nucleic acids) into oligomers, dimers and finally monomers.
Endopeptidase
Protease that cut internal peptide bonds in a peptid chain
Exopeptidase
Protease that cut amino acids from the end of peptide chains.
Fermentation
Anaerobic enzymatic conversion of organic compounds, to simpler compounds.
Gastrin
A hormone produced in the stomach. It increases Hal secretion.
GIP
Glucose-dependent insulinotropic hormone. It is produced in the small intestine in response to carbohydrates, and induces insulin secretion and inhibits emptying of the stomach.
Intrinsic factor
Protein secreted in the stomach, and is needed for the absorption of B12 vitamin (extrinsic factor=
Lactose intolerance
Lactose contende by milk and some dairy products is not metabolized in the gut due to the lack of the enzyme lactase.
Lipases
Enzymes in the pancreatic juice that digest lipids (fat).
Lipogenesis
Synthesis of natural fat from fatty-acids and glycerol.
Mass peristalsis
A fast and more powerful peristaltic wave in the large intestine initiated by the sudden dissension of the (usually empty) duodenum (frequently results in defecation)
Nucleases
Enzymes digesting nucleic-acids (e.g. DNA, RNA)
Parietal cells
HCl producing cells in the stomach
Peristalsis
Worm-like movement by which the alimentary canal or other tubular organs having both longitudinal and circular muscle fibers propel their contents.
Proteases
Enzyme digesting proteins and polypeptides.
Pyloric sphincter
A ring of muscles separating the stomach from the duodenum.
Reflux
The backward flow of stomach content into the esophagus due mainly to weakness of the cardiac sphincter
Secretin
Produced in the small intestine in response to acid, it increases HCO3- *lower 3, upper - *production in the pancreas and inhibits emptying of the stomach
Villus, villi
small, fingerlike, vascular processes found densely packed on the inner wall of the gut increasing the absorptive surface.
