GI Phys 3: Stomach Flashcards
location, function, and secretion of mucous cells and neck cells
located at surface, secrete mucus and bicarb, function is gastroprotection to protect the stomach from itself
location of parietal cells
deeper withi nthe pit
parietal cells secrete what? what is their function
secrete HCl and intrinsic factor. function related to HCl release is protein digestion and sterilization of environement. for IF, the function is nutrient absorption
Chief cells secretion and function
chief cells secrete pepsinogen (a protease). the function is for protein digestion
list the 4 important regulatory cells in the stomach
ECL, neurons, D and G cells
ECL cells secrete what
histamine
function of histamine
important paracrine regulator
neurons secrete what
ach
G cells secrete what
gastrin
d cells secrete
somatostatin which turns off GI activity (suppresses hcl secretion)
location of g and d cells
antrum
how is acid secretion regulated? (3 pathways)
1) paracrine pathways (histamine)
2) endocrine pathways (gastrin)
3) neuronal pathways (ach)
which type of cells are the primary secretory cells of pepsinogen
chief cells. key stimulus = Ach!!!!
Pepsinogen to pepsin - process?
chief cells secrete pepsinogen (inactive). Hcl needed for activation. A lower ph is needed to activate pepsin (1-3). once active, pepsin can activate additional molecules.
acid secretion is regulated directly through:
prostaglandins, which inhibit signaling through the histamine pathway
