Hormone responsible for BP regulation after a fall due to blood loss.

Ans. is'a' i.e., ADH o Blood pressure is regulated by following mechanisms.A) Short term regulation# These mechanisms act immediately and correct the blood pressure quickly. These arei) Baroreceptor reflex: Works during BP range 70-150 mmHg.ii) Chemoreceptor reflex: Works when BP below 80 mmHg.iii) CNS ischemic response: This the only hope of survival when BP is below 40 mmHg.iv) Hormonal release: These are -a) Antidiuretic hormone (ADH) : Increases water reabsorption in kidney.b) Angiotensin II: Causes vasoconstriction.B) Long term regulation# This is the mechanism which takes long time for regulation. This mechanism is present in kidneys. This mechanism adjusts the BP by adjusting volume of extracellular fluid and blood.# Mechanisms arei) Pressure diuresis.ii) Pressure natreuresis.iii) Renin-angiotensin-aldosterone system.Important facto Angiotensin II is involved in short term regulation.o But, full RAA system is involved in long term regulation.