DIGESTION AND ABSORPTION 1 Flashcards
elaboration of fluid (lubricate and moisten food)
salivary gland
elaboration of HCl and digestive enzymes
Stomach
elaboration of bicarbonate and enzymes for intraluminal digestion
pancreas
elaboration of bile acids
liver
storage and concentration of bile
gallbladder
terminal digestion of food and absorption of nutrients
small intestine
absorption of electrolytes
large intestine
expressed on the endothelial cells, smooth muscle, brain and nerve endings
causes dilation of blood vessel
H1
produced from the decarboxylation of histidine, found in skin, lungs, and GIT, released from mast cells, basophils, eosinophils, and enterochromaffin cells
produces H1,H2,H3,H4
hIistamine
expressed in gastric parietal cells and causes release of HCl
H2
parietal cells has 3 receptors
ach, gastrin, and histamine
produces by G cells which are located at the pyloric glands acts on gastrin inhibitor
gastrin hormones
synthesized from tryptophan
upon the action of GIT where there is a peristaltic movement there will be constriction of smooth muscle
serotonin
peptide of 34 amino acids which is cleaved to yield little gastrin which is comprised of 17 residues
big Gastrin
synergistic with CCK
gastrin activates the H2 receptor of parietal hormones and therefore HCl will be released
somatostatin will be released to turn of gastrin release
Gastrin
stimulates gallbladder contraction which releases CCK and pancreatic enzymes
works hand in hand with secretin when taking in a fatty meal and will stimulate the gallbladder to release the bile acid that will emulsify fats
CCK
stimulates duct cells to produce bile acids
functions in gastric emptying
secretin
initiated by sight or taste of food, grumbling sound of stomach
cephalic phase
activates gastric activity of stomach
secretion of Ach, Histamine, and Gastrin
Gastric phase
occurs in the duodenum as a response for the arriving chyme and it moderates the gastric activity by the nervous reflexes and hormones
intestinal phase
conditionally essential protein
arginine, tyrosine, glutamine and cysteine
hydrolyze peptide bonds between specific amino acids throughout the molecule
cleave large polypeptides to smaller oligopolypeptides
endopeptidases
catalyze the hydrolysis of peptide bonds one at a time from the ends of the peptides
exopeptidases
released in pancreatic juices which releases amino acid at the carboxy terminal
carboxypeptidases