What is true of pepsin action? what are the three compartments of the stomach? What is the function of the mucus cells? What is the function of the endocrine cells in the stomach? What is the function of the chief cells? What is the function of the parietal cells? How do hormones control the secretion of acid? Why does the stomach not eat the lining through the acid? What is the purpose of the bicarbonate pump? When/how do ulcers occur in the body?

1. What is true of pepsin action?

pepsin has greater action in the 3-4 pH range

2. what are the three compartments of the stomach?

Fundis (anterior to the esophagus), body (storage portion of the stomach), antrum (thick muscular walled portion of the stomach; powerful intermittent contractions mixed with food and gastric secretions)

3. What is the function of the mucus cells?

produce mucus that prevents acid from coming in contact with the stomach wall

4. What is the function of the endocrine cells in the stomach?

release histamine telling parietal cells to make acid

5. What is the function of the chief cells?

make precursors for pepsin (called pepsinogen) and become active when they com in contact with the parietal cells

6. What is the function of the parietal cells?

make stomach acid

7. How do hormones control the secretion of acid?

ACh or Gastrin prompt histamine release in the endocrine cells --> histamine binds to the H2 receptor --> activating proton pump (stomach acid)

8. Why does the stomach not eat the lining through the acid?

mucus layer blocks acid and pepsin attack on tissue and bicarbonate neutralizes acid diffusion

9. What is the purpose of the bicarbonate pump?

takes up bicarbonate that is made and secreted by the pepsin cells the capillary flows and then is deposited in the mucous lining (helps to neutralize)

10. When/how do ulcers occur in the body?

Occurs when the protective mechanisms in stomach are overwhelmed by acid secretion