Chapter 17: Digestive System Flashcards
phases of gastric secretion (3)
- cephalic
- gastric
- intestinal
cephalic secretion
sight, smell, thought of food triggers parasympathetic reflexes; secretion of gastric juice
gastric secretion
food in stomach stimulates gastrin release, which, in turn, stimulates release of gastric juice
intestinal secretion
good in small intestine stimulates intestinal cells to release intestinal gastrin, which promotes secretion of gastric juice from stomach wall; inhibits gastric secretion
gastric absorption
- pepsin begins breaking down proteins
what does the stomach absorb?
- some water
- some alcohol
- certain salts
- certain fat-soluble drugs
chyme
result of the mixing of food in the stomach with gastric juice
peristaltic waves
push chyme towards pylorus of stomach
enterogastric reflex
when chyme starts to fill duodenum, stretch receptors initiate this response; slows stomach emptying & intestinal filling
pancreas
- endocrine & exocrine
- produces enzymes for breakdown of fats, lipids, and proteins (digestive juice)
acinar cells
make up most of pancreas, and release pancreatic juice into tiny ducts which lead to pancreatic duct
pancreatic duct
empties into duodenum of small intestine
hepatopancreatic ampulla
pancreatic duct & common bile duct join here; dilated tube
hepatopancreatic sphincter
surrounds ampulla; controls movement of bile & pancreatic juice into duodenum
pancreatic juice components (7)
- pancreatic amylase
- pancreatic lipase
- trypsin
- chymotrypsin
- carboxypeptidase
- nucleases
- bicarbonate ions
pancreatic amylase
splits starch and glycogen into disaccharides
pancreatic lipase
breaks down triglycerides
trypsin
digests proteins; released as inactive trypsinogen, which is activated by enterokinase in small intestine
chymotrypsin
digests proteins; released as inactive, activated by trypsin
carboxypeptidase
digests proteins; released as inactive, activated by trypsin
nucleases
digest nucleic acids
bicarbonate ions
make pancreatic juice alkaline; buffer stomach acid
hormones that help regulate release of pancreatic juice
- secretin
- CCK
CCK
stimulates release of pancreatic enzymes
liver
- largest internal organ
- located in RUQ, below diaphragm
- reddish brown color
- can regenerate
4 lobes of liver
- right (larger)
- left
- caudate (minor, near IVC)
- quadrate (minor, near gallbladder)
basic functional unit of liver
hepatic lobule
function of liver in digestive system
secrete bile
