Hormones, Secretions, and Gastric Anatomy

These flashcards cover gastric hormones, cell-specific secretions, primary and secondary active transport mechanisms, and the physiological roles of secretin and pepsin.

Gastrin

A hormone that increases $Ca^{2+}$ uptake and increases $H^+/K^+$ activity via CCK-II receptors.

Somatostatin

A secretion that inhibits $H^+$ and $HCl$ production via SST-R receptors.

Histamine

A secretion that utilizes a g-stimulatory pathway to increase $H^+/K^+$ and $HCl$ via H2-R receptors.

Prostaglandin

A secretion that utilizes an inhibitory pathway to decrease $HCl$ via EP-3 receptors.

Alkaline tide

The process where $HCO_3^-$ exits the cell into the bloodstream as $HCl$ is produced.

Antral D-cells

Cells located in the antrum that produce somatostatin.

Antral/Duodenal G-cells

Cells that produce Gastrin.

Chief cells

Cells that produce pepsinogen.

ECL-cells

Enterochromaffin-like cells that produce histamine.

EC-D-cells

Enterochromaffin cells that produce somatostatin.

S-cells

Cells that produce Secretin to target pancreatic ductule cells.

Parietal cells

Cells responsible for the production of $HCl$.

I-cells

Cells that produce CCK to stimulate the pancreas to release amylase, lipase, and trypsinogen.

Pepsinogen Triggers

The positive triggers for the release of pepsinogen include secretin, Ach, gastrin, and histamine.

Primary Active Transport

Transport involving the direct use of ATP and enzymes for energy coupling, such as the $Na^+/K^+$ ATPase, $Ca^{2+}$ ATPase, and $H^+/K^+$ ATPase.

Secondary Active Transport

Transport with an indirect ATP requirement that uses energy coupling to move substances against a concentration gradient, such as $Na^+$/glucose cotransport or $Na^+/H^+$ counter transport.

Rugae

Folds or ridges in the stomach anatomy located in the body of the stomach.

Secretin (Action on Gastrin)

Inhibits antral G-cells from releasing gastrin to inhibit $HCl$ production.

Secretin (Action on Liver)

Stimulates the liver to produce more bile salts for the digestion of fatty acids (FA).

Secretin (Action on Pancreas)

Stimulates ductal epithelial cells of the pancreas to release $(HCO_3)^-$ to neutralize $H^+$ ions.

Pepsin Activation

The process where proteins in an acidic stomach medium cause the cleavage of pepsinogen into pepsin.

$Na^+/K^+$ ATPase

A primary active transport mechanism where $3Na^+$ leave the cell and $2K^+$ enter.