Epithelial Transport

Question 1

Describe the channels involved in diluting mucus so that you can cough it up.

Answer 1

There is a pump that does 3Na+/2Cl- and 1 K+.

Cl- accumulates in the cell and leaks out on the apical side.

The negative charge causes Na ions and H20 to diffuse through gaps in cells. The H20 then dilutes mucus.

Question 2

How does cholera work?

Answer 2

Cholera is an Adenyl cyclase activator. Because the Cl- leak channel is cAMP dependant (second messanger signal from primary ACh), cholera causes constant diffusion of Cl- ions.

Question 3

What are the main routes for excretion of waste?

Answer 3

15000 mmols Total produced.

1. GI- 30mmols
2. Kidney 1200mmols
3. Lungs ( 14.5 molds of CO2) breathed out.