Secretory Cells of the Stomach

Question 1

Parietal (oxyntic) cells

Answer 1

• HCl- kill bacteria allow activation of pepsin from pepsinogen, and provide low pH for pepsin action
• Intrinsic factor- glycoproteins that bind Vit B12 making it absorbable by the ileum mucosa (NEED THIS). Only found in the stomach- people who have gastric surgery no longer produce this so they have a B12 deficiency.

Question 2

Mucous Neck Cells

Answer 2

• Mucus: protection of the gastric mucosa

Question 3

Peptic (Chief) Cells

Answer 3

• Pepsinogens: In acidic environment they are cleaved to pepsins and they are only active in acidic environments.

Question 4

Enterochromaffin-like (ECL) Cells

Answer 4

*Histamine (Paracrine): acts on the neighboring paracrine cells in order to secrete HCl.

Question 5

D-cells

Answer 5

*Somatostatin (endocrine): inhibits HCl secretion.

Question 6

G- cells

Answer 6

• Gastrin- stimulates ECL cells to secrete histamine and stimulates parietal cells.