List various pathways involved in the homeostatic compensation in the case of severe dehydration.

Explanation

The below flowchart shows the pathways involved in the homeostatic compensation in case of severe dehydration.

i) If there is decreased extracellular fluid volume, it increases sympathetic stimulation and decreases blood pressure and decreases fluid and sodium delivery to the distal tubule.
ii) This enhances secretion of renin.
iii) it converts angiotensinogen to angiotensen 1 and angiotensen 1 to angiotensen 2.
iv) This increase in the angiotensen 1 increases the secretion of aldosterone which increases the reabsorption of sodium by distal tubule and increased secretion of potassium.
v) The increase in angiotensen 2 increases thirst and reabsorption of sodium in the PCT.