Question

Describe the mechanism for regulation of fluid volume in mammals that involves the hormone mechanisms of the kidney, and any other organs or structures.

a) describe the hormones or chemicals involved

b) state the tissue of origin for these hormones/chemicals

Answer 1

a) The hormones which are involved in the fluid volume regulation are aldosterone , ADH and ANH

Aldosterone : The sodium water balance is maintained aldosterone by the activation of the renin angiotensin aldosterone system.This is regulated by negative feedback mechanism .Excess loss of fluid causes the loss of sodium and water and this is overcome by the reabsorption of sodium and water and kidney tubules by the activation of RAAS.

ADH: Excess fluid loss causes the release of ADH and this has anyidiuretic effect wherein the water transit piton is increased by changing the permeability of the distal kidney tubules.

ANH:They elicit an opposing effect to that of aldosterone by inhibiting the uptake of sodium and water in situations like edema.It inhibits the secretion of renin.

b)

Origin of

Aldosterone : Zomato glomerulosa of adrenal cortex

ADH: Posterior pituitary of hypothalamus

ANF:Atria of heart