2.1. The Loop of Henle - Tubule Function

Question 1

What is the function of the Proximal Tubule?

Answer 1

This is the major site of reabsorption

Question 2

What is reabsorbed at the proximal tubule?

Answer 2

1. NaCl
2. H2O
3. Nutritionally important substances

Question 3

What percentage of NaCl and H2O are reabsorbed here?

Answer 3

65-75%

Question 4

What happens to the protein that does pass through the glomerular capillaries, into the Bowman’s Capsule?

Answer 4

These are reabsorbed by a Tm carrier mechanism

Question 5

What protein usually gets through the glomerular capillary filtration?

Answer 5

Albumin

Question 6

What percentage of proteins present at the glomerulus will pass through?

Answer 6

About 0.5%

Question 7

If a drug / pollutant is lipid soluble (non-polar) is it easily secreted?

Answer 7

No

Question 8

Why are lipid solbule (non-polar) drugs/pollutants hard to secrete?

Answer 8

1. The removal of H2O in the proximal tubule establishes a concentration gradient in favour of reabsorption
2. These would therefore just diffuse back into the capillaires

Question 9

What happens to the lipid soluble (non-polar) drugs/pollutants?

Answer 9

The liver metabolizes them to polar compounds which will facilitate there secretion