2. Digestion Flashcards
(24 cards)
Absorption
Transport of the digested nutrients (amino-acids, sugars, fatty-acids) 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
Ring of muscles separating the esophagus from the stomach.
CCK
Cholecystokinin - produced in the small intestine in response to lipids and proteins, it 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 of the nutritive macromolecular polymers (proteins, carbohydrates, lipids, nucleic acids) into oligomers, dimers and finally monomers.
Endopeptidase
Protease that cuts internal peptide bonds in a peptid chain
Exopeptidase
Protease that cuts amino acids from the end of peptide chains
Fermentation
Anaerobic enzymatic conversion of organic compounds, especially carbohydrates, to simpler compounds usually by bacteria (e.g. fermentation of cellulose in the alimentary canal).
Gastrin
Hormone produced in the stomach - increases HCI secretion.
GIP
Glucose-dependent insulinotropic hormone - produced in the small intestine in response to carbohydrates. It induces insulin secretion and inhibits emptying of the stomach.
Intrinsic factor
Protein secreted in the stomach, needed for the absorption of B12 vitamin (extrinsic factor)
Lactose intolerance
Lactose contained by milk and some diary products is not metabolized in the gut due to lack of the enzyme lactase.
Lipases
Enzymes in the pancreatic juice that digest lipids (fat)
Lipogenesis
Synthesis of neutral fat from fatty-acids and glycerol.
Mass peristalsis
A fast and powerful peristaltic wave in the large intestine initiated by the sudden distention of the (usually empty) duodenum (frequently results i defecation)
Nucleases
enzymes digesting nucleic-acids (e.g. DNA, RNA).
Parietal cells
HCI producing cells in the stomach
Peristalsis
wormlike movement by which the alimentary canal or other tubular organs having both longitudinal and circular muscle fibers propel their contents
Proteases
Enzymes digesting proteins and polypeptides
Pyloric Sphincter
ring of muscles separating the stomach from the duodenum.
Reflux
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 production in the pancreas and inhibits emptying of the stomach.
Villus, villi
Small, finger-like, vascular processes found densely packed on the inner wall of the gut increasing the absorptive surface.
