Control of Digestion Flashcards
(20 cards)
What are the accessary glands for the small intestine?
- Liver
- Gallbladder
- Pancreas
What is the pH roughly in the small intestine?
7
What occurs if the chyme contains carbs?
Gastric inhibitory peptide (GIP) and glucagon like peptide 1 (GLP-1) released from duodent K and L cells
What does GIP/GLP-1 stimulate?
Pancreatic insulin secretion
What does the acidic nature of chyme trigger?
Secretin release from S cells in duodenum
What does secretin trigger?
The release of bicarbonate from the pancreatic duct cells to neutralise acid
How is bicarbonate produced?
Via carbonic anhydrase
What occurs if the chyme contains fats?
Triggers cholecystokinin (CCK) release from duodenal I cells
What does CCK stimulate?
- Pancreatic enzyme secretion
- Gallbladder contraction to release bile
- Relaxes the sphincter of Oddi
What is the sphincter of Oddi?
A circular muscle that controls the flow of bile and pancreatic juices from the liver and pancreas into the small intestine
How is trypsinogen activated?
By enteropeptidase which is found on the brush border (micro villi)
What is segmental contractions in the small intestine?
Alternating sections contract and relax resulting in the mixing of chyme with digestive enzymes and bicarbonate
Where does digestion of carbohydrates occur?
- Begins in the mouth by amylase
- Stops in the stomach
- Pancreatic amylase converts polysaccharides to disaccharides
- Intestinal brush border enzymes coverts disaccharides to monosaccharides
Where does digestion of proteins occur?
- Starts in the stomach by pepsin
- In the duodenum digested by trypsin, chymotrypsin and carboxypeptidase
What are endopeptidases?
They cut the protein chain in the middle
What are exopeptidase?
They cut the end of the protein chain
What are the two endopeptidases in the duodenum?
- Trypsin
- Chymotrypsin
What is the exopeptidase in the duodenum?
Carboxypeptidase
What is bile comprised of?
- Bile salts
- Cholesterol
- Bilirubin
Where is bile stored and concentrated?
Gallbladder
