Osmoregulation Flashcards
Where is water balanced
In distal convoluted tube and collecting duct
Permeability can be altered
Water loss hormone
Anti diuretic hormone
Produced by hypothalamus
Secreted by posterior pituitary gland
Adh storage
In vesicles in axon terminals
At the posterior pituitary gland
How is water potential monitored
By cells in hypothalamus called osmoreceptors
ADH action stage 1
Released from ppt into blood
Travels to collecting duct of the kidneys
Binds to receptors in cell membrane of tubule cells
ADH action stage 2
Binding triggers cAMP
Triggers cascade of events
cAMP triggers….
Vesicles to fuse to collecting duct membrane containing aquaporins
Water then travels out collecting duct into medulla then into the blood
Drinking a lot
Water potential of blood rises
ADH levels fall levels of cAMP fall
Water channels enclosed in vesicles
Collecting duct is impermeable
Result in production of large volume of dilute urine
Maintains wp of blood and tissue fluid