Question

If we estimate that total blood volume is 7% of body weight calculate the blood volume in a 200 lb man and a 130 lb woman. What are their plasma volumes if man’s hematocrit is 52% and woman’s is 41% Would you expect to find valves in the veins leading from the brain to the heart? Defend your answer. Why would it be more efficient to put ACE in the pulmonary vasculature than in systemic vasculature?

Answer 1

Male of 200lb

Blood volume = 200× 7/100 = 14 lb.= 6.3 litre.

One litre equals 0.45 litres.

Hematocrit 52%

Plasma volume = total blood volume (1-hematocrit)

= 6.3(1- 0.52)=3.02 litres

130 lb female.

Blood volume = 130× 7/100= 9.1lb= 4.1 litre

Hematocrit = 41%

Plasma volume = 4.1(1- 0.41)= 2.41 litres.

No there is no need of valves in the veins that carry blood from brain to heart. These valves are for the pumping of blood to the heart. But in the case of veins from vein the blood flow by the aid of gravity.

The ACE converts the the Angiotensin l to angiotensin II. So this angiotensin II is a vascular growth mediator of the pulmonary vasculature. So ACE contribute more in pulmonary vasculature.