10.2 - Kidney and Water

Question 1

What is the stimulus for hypothalamus in kidney and water?

Answer 1

Hypothalamus detects an INCREASE in solute concentration in blood ( low [water] )

Question 2

What does hypothalamus do when it has this stimulus?

Answer 2

• Directs posterior pituitary to release ADH (anti-diuretic hormone) into the blood

Question 3

What does ADH do?

Answer 3

Targets collecting ducts of nephron, to be directed to REABSORB more water back into the blood (less water in urine!)
-> this lowers [solute] in blood

Question 4

What is the negative feedback of the ADH process?

Answer 4

Hypothalamus detects decrease in [solute] and direct posterior pituitary gland to stop releasing ADH

Question 5

What is an anti-diuretic?

Answer 5

Causes H2O reabsorption in collecting duct

Question 6

Examples of diuretics and what they do

Answer 6

Diuretic: releases more urine to decrease blood pressure
Examples: alcohol, coffee

Question 7

What does diabetes insipidus do?

Answer 7

Insufficient release of ADH from pituitary (acts as diuretic)

Question 8

Role/process of ADH when: salt eaten/too much sweating

Answer 8

1. water content in blood is low
2. brain releases a lot of ADH
3. high volume of water reabsorbed by kidney
4. small volume of CONCENTRATED urine passed to bladder
5. high volume of water passes into blood

Question 9

Role of ADH when: too much water is drunk

Answer 9

1. Water content of blood is too high
2. Brain releases little ADH
3. Low volume of water reabsorbed by kidney
4. High volume of DILUTE urine passed to bladder
5. Low volume of water passes into blood