mucous cells produce alkaline mucus where gastric glands within gastric pits secrete gastric juices containing intrinsic factor - which is needed to absorb vitamin B12
describe the composition of gastric pits
gastric pits produce pepsinogens - protein digesting enzymes
parietal cells = produce HCL
entereoendocrine cells - produce gastrin hormone
describe the composition of the small intestine
consists of a muscular tube from the pyoloric sphicter to the ileocecal valve which is suspended from the posterior abdominal wall by the mesentary
it is the site of nutrient absorption into blood
describe the subdivisions of the stomach
duodenum
jejunum
illeum
where the large intestine meets the ileocecal valve
chemical digestion in small intestine
includes enzyme produced by intestinal cells, pancreas
pancreatic ducts carry enzymes to duodenum which contains bile
made in liver and stored in gall bladder where it enters in the duodenum
describe the absoprtion in small intestine
greater surface area for absorption of nutrients due to
microvilli - tiny projections of plasma membrane.
villi - fingerlike projections of mucosa with capillaries
circular folds - folds o mucosa and submucosa
describe the physiology of large intestine
larger in diameter, shorter length than small intestine
illeocecal valve to anus
expels indigestable food reside from the body (producing feces)
colon
ascending colon includes digested food where it travels up R side of abdominal cavity.
transverse colon - travels across
descending colon - down L side
sigmoid colon - S-shaped, enters pelvis
anus
external anal sphincter = skeletal muscle, voluntary control