Stomach

What allows the gastroesophageal sphincter of the stomach’s fundus to relax and fill?

The medulla and vagus nerve mediate receptive relaxation of the gastroesophageal sphincter.

What cell population helps the stomach with its churning function?

Gastric cells

Name the cell and the hormone it secretes to stimulate gastric motility.

DNES cells of the stomach produce the homrone serotonin to stimulate gastric motility

What causes the stomach to empty chyme into the duodenum of small intestine?

The stomach empties chyme into the duodenum when the duodenum’s sensory receptors detect stimuli that triggers a negative feedback loop that delays gastric emptying.

What stimuli delays gastric emptying?

A high degree of stretch, low pH, high lipid composition, and/or a high solute concentration

What mediates the negative feedback loopl to delay gastric emptying?

The vagus nerves and hormones secreted by the duodenum mediate the negative feedback loop. Hormones include secretin, cholecystokinin, and gastric inhibitory peptide.

During the cephalic phase, what do the vagus nerves release to cause the parietal cells in the gastric gland to secrete H+?

The vagus nerves release ACh onto parietal cells to secrete H+

During the cephalic phase, the vagus nerves release another substance to cause the DNES G cells in the gastric gland to secrete H+. What substance is this?

The vagus nerves secretes gastrin which causes DNES G cells to secrete H+

Somatostatin, a hormone that inhibits acid secretion, is produced by a DNES cell. What nerve inhibits the release of a somatostatin during the cephalic phase?

The vagal nerve inhibits somatostatin, which has the effect of increasing hydrogen ion secretion.

In the gastric phase, what releases ACh to elicit a net effect of increasing acid secretion?

Distension in the stomach wall stimulates neurons of the ENS