Physiology 3120 Lecture Notes - Pancreatic Duct, Pancreatic Juice, Acinus
26 Nov 2011
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Document Summary
Down-regulation of gastric acid secretion: very close to the secretory cells of the pyloric gland area is another cell that releases somatostatin (normally released by pancreas, but has a somewhat ubiquitous secretion) Also under cholinergic control, but ach inhibits somatostatin release. Somatostatin is inhibitory to acid secretion: as stimuli that activate cholinergic mechanisms, the cholinergic nerves are not activated, and have less. Less release of acid (from oxyntic) and gastrin (from g cell) Somatostatin is disinhibited; and inhibits the release of gastrin. Eliminate the potentiated response of acid secretion. The somatostatin cell is ph-sensitive ph in stomach before eating is somewhere around 4-6 (foods such as proteins or carbs are relatively good buffers) Eventually, so much acid is secreted that the buffering capacity is overwhelmed and the ph begins to drop; eventually, you reach the ph switch (between 2. 4-2. 7) that turns on the somatostatin cell, which inhibits gastrin. Antrum = archaic term for pyloric gland area.
