Tubular Function L of H

Question 1

what does the ascending portion do?

Answer 1

-chucks out salt

Question 2

what does the descending portion do?

Answer 2

• chuck out water

Question 3

what vessels are wrapped around the Loop of Henle

Answer 3

• vassa rector

Question 4

what is the purpose of the L of H

Answer 4

• allows as much water to be reabsorbed by collecting ducts and DCT
• also if theres already too much water, allows collecting duct to remove the excess water

Question 5

what is the osmolality like at the bottom of the L of H

Answer 5

• very high

- filtrate v concentrated, water chucked out

Question 6

what is the osmolality like at the top of the L of h

Answer 6

• very low
• dilute filtrate
• water come in, salts chucked out

Question 7

what are the channels in ascending side good at?

Answer 7

-throwing out salts into interstitum (NaCl in particular)

Question 8

why does water not follow?

Answer 8

• no aquaporins, water pores

- cells tightly packed together - doesn’t allow water to follow

Question 9

why does water come out in descending L of H

Answer 9

• salt in intersitium
• therefore water comes out
• a lot of aquaporins and water pores

Question 10

how do drugs work on the L of H?

Answer 10

1. drug blocks the sodium/potassium channel in ascending loop of H
2. this means no salt is extruded in intersitium
3. no corticomedullary gradient created
4. no salt gradient surrounding collecting duct
5. no water moves out of collecting duct bc no salt gradient exists
6. water passed into urine, plasma vol drops and therefore b.p. drops.