Stomach Flashcards
HCL…
Aids digestion by activating pepsinogen
Aids breakdown of connective tissue
Non specific defence mechanism
Types of gastric mucosa and their secretions.
Surface epithelial, mucus
Mucous neck, mucus
Parietal, HCL and intrinsic factor
Chief cells, pepsinogen
Vagal actions and effects on HCL production
GRP on gastrin acts on CCK2 on histamine and parietal cells
Ach on muscarinic receptors on histamine and parietal cells (increases Ca2+)
Histamine acts on H2 receptors on parietal cells to increase cAMP.
Somatostatin inhibits gastrin release (D cells in Antrum)
Inhibition of gastric secretions
Removal of peptide fragments
Removal of food -> decrease pH, when pH is bellow 2 gastrin release inhibited by somatostatin.
Distension of duodenum-> hormone release->cholecystokinin->inhibits gastrin release
Protection of gastric mucosa
Luminal membranes of gastric mucosa impermeable to H+
pH bellow 2 inhibits gastrin release
Mucus release from surface epithelium
Rapid repair, prostaglandin production, local vasodilation.