Exam Five - Digestive System Two Flashcards
What are the three functions of the stomach (gastric phase)?
1 - storage
2 - digestion
3 - defense
digestive activity in the stomach begins with ______________ of cephalic phase and then food in stomach initiates ______ of gastric phase
- long vagal reflex
- short reflexes
what is the name of the sphincter that controls food entering the stomach?
lower esophageal sphincter
what is the name of the sphincter that controls food entering the duodenum?
pyloric sphincter
The surface area of the stomach is increased by:
invaginations called gastric glands
G cells secrete?
Gastrin
parietal cells secrete?
gastric acid (HCL)
and intrinsic factor (go into food and save B12 from acid)
chief cells secrete
pepsinogen and gastric lipase
D cells secrete?
somatostatin (shuts down motility and acid production; fewer of these cells so have a delayed response)
ECL secretes
histamine (secretion of acid and mucus)
stomach protects itself with a ________ barrier which prevents auto________–
mucus bicarbonate
autodigestion
mucus cells secrete ______ and ________
mucus and bicarbonate
what receptor is not functional in cystic fibrosis?
CFTR, prevents Cl from traveling to lumen
Why is a nonfunctional CFTR receptor in cystic fibrosis a bad thing?
it prevents Cl from going into lumen, which means water won’t follow, which means the mucus layer is too thick which causes severe dysfunction
why is motility in the small intestine controlled?
segmental and peristaltic contractions ensure small intestine isn’t overwhelmed by chyme
how does the small intestine maximize surface area?
microvilli, villi, and crypts
(brush border)
where do nutrients absorbed in small intestine go?
most go to hepatic portal system
fats use lymphatic circulation to enter circulatory system
what are some functions of the liver
filters blood (biliruben)
releases glycogen
filters nutrients absorbed by intestines
What are 5 intestinal secretions that promote digestion?
1 - digestive enzymes
2 - bile
3 - bicarbonate secretion
4 - mucus
5 - isotonic NaCl secretion
what is the endocrine function of the pancreas?
islet cells
secretes insulin and glucagon
what is the exocrine function of the pancreas?
acini cells
secretes digestive enzymes (trypsinogen = master enzyme) and sodium bicarbonate
T or F: GALT is the largest part of the immune system and aids in fat digestion
true!
T or F: chymotrypsinogen is the master enzyme?
false, trypsinogen is!
The hepatic system includes:
liver, gall bladder, and hepatic portal system
what is the function of the gall bladder?
store bile formed in liver
what happens when you remove the gall bladder
it becomes very difficult to digest fatty foods
what is the largest internal organ
liver, gets larger with increased poison processing
_________ takes bile made in the liber to the gallbladder for storage
common hepatic duct
__________ takes bile from the gallbladder to the lumen of the small intestine
common bile duct
_________ brings oxygenated blood containing metabolites from peripheral tissues to the liver
hepatic artery
_____________ is rich in obsorbed nutrients from the GI tract and contains hemoglobin breakdown products from the spleen
hepatic portal vein blood
__________- controls release of bile and pancreatic secretions into the duodenum
sphincter of oddi
_________ coat lipids to make emulsions
biles salts
T or F: bile is the route of excess cholesterol disposal
T, also disposes bilirubin
most lipids are ___ and must be emulsified to facilitate digestion in the aqueous environment of the intestine
hydrophobic
_______ are small discs with bile salts, phospholipids, fatty acids, cholesterol, and mono/diglycerides
michelles
_______ and _______ digest triglycerides
lipase and colipase
T or F: only monosaccharides can transfer through small intestine cells
T
