Lecture 65

Question 1

What is the purpose of the Loop of Henle?

Answer 1

To create a high osmotic force in the medulla of the Kidney

Question 2

Water balance:

Input:

____
__________

Output:

__________
__________
__________
__________

Answer 2

Water balance:

Input:

diet
metabolism

Output:

Urine
lungs
skin
faeces (not much)

Question 3

A negative water balance will be most obvious as:

Answer 3

an increase in Intracellular volume

where most of the water is

Question 4

Osmoreceptor cells respond to:

also, where are they located:

Answer 4

Respond to changes in cell size

Located in the hypothalamus

Question 5

A negative water balance will normally result in:

in terms of urine

Answer 5

Concentrated Urine

Question 6

What things are needed to produce concentrated urine?

Answer 6

Vasopressin (ADH)

Question 7

If someone had no vasopressin available, what sort of urine would they pass?

Answer 7

Lots and lots and lots of dilute urine

Question 8

Vasopressin is released if ECF volume ____ ______ a set point - acts to allow more _____to be reabsorbed

Answer 8

Vasopressin is released if ECF volume drops below a set point - acts to allow more water to be reabsorbed

Question 9

Urine osmolality ranges from _-____ mOsm/kg.H2O

Answer 9

Urine osmolality ranges from 3-1200 mOsm/kg.H2O

Question 10

Tubular fluid leaving the loop of Henle is normally:

Answer 10

Dilute

Question 11

Isosmotic fluid leaving the proximal tubule becomes progressively more _________in the descending limb

Answer 11

Isosmotic fluid leaving the proximal tubule becomes progressively more concentrated in the descending limb

Question 12

The thick ascending limb is used to _______solutes that have become concentrated

Answer 12

The thick ascending limb is used to remove solutes that have become concentrated

(ions reabsorbed but no water)

Question 13

The medullary concentration gradient is mostly the result of:

Answer 13

Sodium and Urea

Question 14

True or False:

Salt is reabsorbed in the ascending limb

Answer 14

True

Question 15

What things are needed to produce concentrated urine

out of:
Na/K/Cl co-transporter
aquaporin
cAMP4

Answer 15

Na/K/Cl co-transporter
aquaporin
cAMP4

Question 16

True or False:

Vasopressin –> Vasopressin receptor –> cAMP (as messenger) –> storage vesicles with Aquaporin 2 –> exocytosis of vesicles –> more water reabsorbtion

Answer 16

True

Question 17

With maximal __________, the collecting duct is freely permeable to water. Water leaves by osmosis and is carried away by the vasa recta capillaries. Urine is __________

Answer 17

With maximal Vasopressin, the collecting duct is freely permeable to water. Water leaves by osmosis and is carried away by the vasa recta capillaries. Urine is concentrated