The Gastrointestinal System Flashcards
Define digestion
breakdown of foods
mechanical and chemical
the four layers of the alimentary canal
mucosa (surface epithelium)
submucosa (glands, blood vessels, lymphatic vessels, nerves)
adventitia (muscular layer = movement)
serosa (serous fluid that protects underlying tissue)
secretion
release of water, acids, buffers, enzymes, salts
absorption
movement of organic substrates into the interstitial fluid
excretion
removal of waste products
propelling movements of the digestive tract
segmentation (small intestine)
peristalsis
three types of salivary glands
parotid
submandibular
sublingual
folds of the stomach
rugae
where does protein digestion begin?
stomach
regions of the stomach
cardiac, fundic, body, and pyloric regions
what is chyme?
semiliquid mass
digested food (broken down and mixed with digestive juices)
parietal cells
found in stomach
hydrochloric acid
intrinsic factor (absorbs vitamin B12)
pernicious anemia
condition where parietal cells are attacked and intrinsic factor is not made
cannot absorb vitamin B12, an important requirement in red blood cells
chief cells
found in stomach
pepsinogen -> pepsin
endocrine cells
found in stomach
gastrin (movement of stomach)
secretin (stimulates secretions)
this hormone stimulates production of pancreatic secretions and gallbladder contractions
cholecystokinin
gastric inhibitory peptide
hormone that inhibits both gastric secretion and motility
three portions of small intestine
duodenum
jejunum
ileum
goblet cells
produce protective mucus lining
beginning portion of large intestine
cecum
four portions of colon or large intestine
ascending colon
transverse colon
descending colon
sigmoid colon
rectum
strate muscular tube that ends at anus
stores stool
anal canal
very short
sphincters = internal and external for defecating
bile
made by liver
stored by gallbladder
cholecystokinin releases bile to small intestine