Question

If a person has a stroke volume of 70ml with a heart rate of 60bpm, how much blood is supplied to the kidneys each minute[A]in milliliters, and how much plasma is supplied each day [B] in liters assuming a hematocrit of 40%and what percent of the plasma is supplied each day [B] in liters assuming a hematocrit of 40% and what percent of the plasma is filtered each day [C]

Answer 1

The cardiac output is =70*60 ml =4200 ml

As,kidney get about 25% of blood of total cardiac volume ,then the blood will goes to kidney will be =(25*4200)100 ml =1050 ml.

Plasma volume will be 1050(100-40)/100 = 630 ml in a minute .

In 24 hours the plasma volume will be =630*60*24 ml =907200 ml = 907.2litre.

In each day ,180 litre is filtered as it is known that in kidney only plasma is filtrated and the volume of plasma passes through the kidney each day is 907.2 litre.

So the percentage of plasma filtered is (180/907.2)*100 =19.84 % about 20 percent.