Digestion 112 Final Wilson Flashcards
ingestion,
taking food into the mouth (eating)
mechanical digestion
consists of movements of the GI tract that aid in chemical digestion
chemical digestion,
series of catabolic (hydrolysis) reactions that break down large carbohydrate, lipid, and protein food molecules into smaller molecules that are usable by body cells
propulsion,
result from the alternating contraction and relaxation of the smooth muscle
secretion,
the release, by cells within the walls of the GI tract and accessory organs, of water, acid, buffers, and enzymes into the lumen of the tract
defecation,
emptying of the rectum, eliminating indigestible substances from the GI
peritoneum,
membranes of the digestive system
mesentery,
double layer of membrane; back to back
omentum,
tethers stomach to other digestive organs
adventitia,
ordinary fibrous CT that is found in esophagus and retroperitoneal organs
amylase,
begins starch digestion at pH 6.5 or 7.0 found in mouth
lipase,
- Secreted by glands in tongue
* Begins breakdown of triglycerides into fatty acids and glycerol
protease,
digestive enzyme that breaks down protein
nucleases,
breaks down nucleic acids
deglutition,
the bolus is swallowed
peristalsis,
propels chyme onward through the intestinal tract
bolus
Mass of food prepared by the mouth for swallowing
chime,
creamy paste that food is converted into
rugae,
Folds that flatten when filled with bolus
emesis,
reflexive emptying of stomach thru the esophagus and pharynx (vomiting)
plicae circularis,
Permanent ½ inch tall folds that contain part of submucosal layer
villi,
1 mm tall on surface of plicae circolarus that contains vascular capillaries and lacteals (lymphatic capillaries)
microvilli,
Tiny projections on the surface of each cell of villus
hepatocytes
liver cells
bile,
greenish-yellow or brownish fluid produced in and secreted by the liver, stored in the gallbladder, and released into the small intestine
bile canaliculi,
Tiny canals
hepatic portal vein,
carries nutrient rich venous blood, from the small intestine, to the liver