Multiple Questions from the assignment.

[Matthew Lockhart]

Seem to be having trouble finding the information for question 4, both
a) and b). (Is this the one that was unnecessary to be finished?)

For question 5, i was wondering if there was any other structure of
the collecting duct that we needed to know, other than that it is
permeable to water with ADH. (That is on the PLO)

10c) This is just a confirmation on my answer. The question is asking
about how the Loop of Henle contributes to the production of urine.
Does it contribute by just creating a saltier environment: increasing
the release of water in both the ascending loop of henle, and the
collecting duct. Making a higher urine/salt, concentration? (or helps
by preservation of water)

Thanks a bunch.

[Scott Harkness]

Dont bother with #4 but...
Urea passively diffuses back into the blood since the urea
concentration is low in the blood. To keep the urea in the tubule ATP
would be needed to pump it back in. waste of ATP energy

For Question #5...no just that it is permeable to water when ADH binds
to proteins

10. A drop in blood pressure occurs in the afferent arteriole.

a. What will happen to pressure filtration and therefore urine
production?.
-less "stuff" filtered into the nephron...ie) less urine volume due to
less water
b. What homeostatic mechanisms act on the kidney to help to return
the blood pressure to normal?
Talk about aldosterone and ADH...increase secretion to increase volume
in blood
c. Explain how the Loop of Henle contributes to the production of
urine which is much saltier than body fluids.
Draws water out of the tubule and back into the tissues of the
kidney...which makes the urine more concentrated (regardless of the
salt that leaves on the ascending end)

Hope it helps

Harkness