Kidney Osmoregulation

Question 1

Osmoregulation

Answer 1

Control of water potential in the body by controlling levels of both salts and water

Must be maintained to prevent water entering cells (lysis) or leaving cells (crenation)

Question 2

How we gain and lose water

Answer 2

Gain :
•food
•drink
•respiration

Lose : 
•urine 
•sweat
•water vapour in inhaled air 
•faeces

Question 3

Negative feedback if u drink less water ( higher water potential of blood )

Answer 3

• detected by osmoreceptors in hypothalamus
• less ADH released by posterior pituitary
• walls of collecting duct less permeable
• less water reabsorbed
• higher volume of urine
• lowers water potential of blood

Question 4

Negative feedback if u drink more water ( lower water potential of blood )

Answer 4

• detected by osmoreceptors in hypothalamus
• more ADH released from posterior pituitary
• walls of collecting duct more permeable
• more water reabsorbed
• smaller volume of urine
• high water potential of blood

Question 5

How it’s detected by hypothalamus

Answer 5

When low water potential, osmoreceptors lose water and shrink

Stimulate neurosensory cells to produce
anti diuretic hormone from posterior pituitary

Carry action potentials down their axons and release ADH by exocytosis