Extra Information for Unit 3 Exam

Question 1

Cells in Gastric Gland

• Mucous neck cells
• Parietal cells
• Chief cells
• Enteroendocrine cells

Answer 1

Mucous neck cells-secret mucus
Parietal cells-secrete hydrochloric acid and intrinsic factor. Instrinsic factor captures vitamin B12 that allows RBC production.
Chief cells-secrete pepsinogen
Enteroendocrine cells-secrete gastrin

Question 2

Goblet cells

Answer 2

secrete mucus

Question 3

Paneth cells

Answer 3

inhibit microbial invasion

Question 4

Stem cells

Answer 4

dividing to create new population of simple columnar epithelium.

Question 5

How is the small intestine specialized for absorption?

Answer 5

It contains microvilli that increase surface area. It also contains alots of blood capillaries for transportation of food molecules all over the body.

Question 6

Mucosal Barrier (protection of stomach against low pH)

Answer 6

• layer of bicarbonate rich mucus produced by mucus cap cells to neutralize acid in stomach.
• tight junctions between epithelial cells
• damaged epithelial cells are quickly replaced by stem cells

Question 7

Duodenum protections from acidic chyme

Answer 7

-duodenal glands secreting alkaline mucus neutralize acidic chyme

Question 8

How T3 and T4 are made?

Answer 8

Follicular cells secrete thyroglobulin into the lumen. Iodide from the capillary goes through the follicular cells and become iodine when it reaches lumen. Thyroglobulin and iodine combines and becomes the colloid. Colloid is endocytosed into follicular cell and combine with a lysosome. Lysosome enzyme cleave colloid which become T3 and T4. T3 is ten time more active than T4.