Vocab. Word | Definition |
active transport | the movement of particles via a carrier protein across cell membranes and epithelial layers; requires expenditure of energy. |
amylase | an enzyme that is secreted in saliva and from the pancreas and catalyzes the hydrolysis of starch. |
brush border | the microvilli that greatly increase the surface area of intestinal mucousal cells |
chelation | the process by which a mineral is bound to a ligand-usually an acid, an organix acid, or a sugar- so that it is in a form capable of being absorbed into intestinal cells. |
cholecystokinin (CCK) | hormone secreted by the proximal small bowel and stimulates pancreatic secretion of enzymes ( and some bicarbonate & H20), simulates gallbladder contraction, slows gastric empyting, stim. colonic activity, may regulate appetite |
chyme | the semifluid, gruel-like material produced by the gastric digestion of food. |
colonic salvage | the process of fermenting and absorbing end products of dietary CHOs, fiber, and amino acids in the small intestine |
enterogastrone | hormone secreted by the duodenal mucosa in response to the presence of fat in the duodenum; inhibits gastric secretion and motility, slowing the delivery of additional lipids into the duodenum |
facilitated diffusion | the movement of particles across a membrane via a transporter or carrier protein |
gastrin | a hormone that is produced by the antral mucosa of the stomach and stimulates gastric secretions and motility. |
glucagon-like peptide 1 (GLP-1) | hormone released from the intestineal mucosa that decreases gastric emptying, lowers glucagon secretion, stimulates insulin secretion, and increases insulin sensitivity and satiety. |
glucose-dependent insulinotropic polypeptide (GIP) | hormone that is released from the intestinal mucosa in the presence of glucose, fat, and/or protein and increases insulin release by pancreatic islet cells. |
lactase | an intestinal enzyme that hydrolyzes lactose into glucose and galactose |
maltase | an intestinal enzyme that hydrolyzes maltose into glucose |
micelle | a complex of primarily free fatty acids, monoglycerides, and bile salts that allow lipids to be absorbed into intestinal mucosal cells |
microvilli | minute cylindrical processes that are found on the surface of the intestinal cells and greatly increase their absorptive surface area |
motilin | a polypeptide gastrointestinal hormone that promotes gastric emptying and intestinal motility. |
pancreatic lipase | an enzyme in pancreatic juice that hydrolyzes the ester linkages between fatty acids and glycerol |
parietal cells | large cells that are scattered along the walls of the stomach and secrete hydrocholoric acis in gastric juice |
passive diffusion | the random movement of particles through openings in cellular membranes according to electrochemical and concentration gradients |
pepsin | a protease active only in the acid environment of the stomach serves to change the shape and size of some proteins in a meal |
peristalsis | the movement by which the alimentary canal propels its contents |
prebiotic | food, usually CHOs or specific oligosaccharides (fructooligosaccharides, insulin) from vegetables, grains, and legumes; may also include resistant starch,soluble dietary fiber, and malabsorbed sugards that are preferred energy source for good GI microbes |
probiotic | food or concentrate of live organisms that contribute to a healthy microbial environment and suppress potential harmful microbes |
proteolytic enzymes | the enzymes trypsin, chymotrypsin, and carboxypeptidase, all of which break down protein into proteoses, peptones, peptides, and amino acids |
secretin | a hormone released from the duodenal wall into the bloodstream that stimulates the pancreas to secrete water and bicarbonate and inhibits gastrin secretion |
somatostatin | a polypeptide hormone secreted from the stomach, sm. intestine, and pancreas that tends to inhibit other fastrointestinal secretions and motility |
sucrase | the intestinal enzymes that hydrolyzes sucrose into glucose and fructose |
synbiotic | a combination of probiotics and prebiotics of a long-chain inulin-type fructans |
villi | the numerous fingerlike projections that cover the surface of the small intestine mucosa |