The mechanism of ADH action Flashcards
1
Q
Where is ADH released from?
A
The pituitary gland
2
Q
Where does ADH have an effect?
A
The collecting duct
3
Q
Outline the mechanism of ADH
A
1) Binds to the receptors on the cell membrane and triggers the formation of cAMP as a second messenger inside of the cell.
2) cAMP causes the vesicles in the cells in the lining of the collecting duct to fuse with the cell surface membranes on the side of the cell in contact with the tissue fluid of the medulla.
3) The membranes of these vesicles contain aquaporins, when they are inserted into the cell surface membrane, they make it more permeable to water.
4) This provides a route for water to move out of the tubule cells into the tissue fluid of the medulla and the blood capillaries by osmosis.
