Question

Calculate the mass of the blood in arteries of systemic circulation of a person whose body mass is 60 kg?

If the mass of the pulmonary blood of a person is 1.3 kg find (a) the mass of the person

(b) the mass of his systemic blood.

Answer 1

There are two types of circulation in blood: Systemic circulation in the rest of the body and the pulmonary circulation in the lungs. Blood volume is not uniformly distributed in systemic and pulmonary circulation.

1) In circulation, mass of blood is approximately 7% of total body weight. Volume of blood is 100/100. Blood volume in systemic circulation is 80/100 of total circulation blood volume. In arteries of systemic circulation, blood volume is 15/100 of systemic circulation.

Mass of blood in arteries of systemic circulation= Mass of blood in systemic circulation X 15/100

Mass of blood in systemic circulation= Mass of blood in total circulation X 80/100

Calculating,

Mass of blood in total circulation= Body weight X 7/100= 60 X 7/100= 4.2 Kg

Mass of blood in systemic circulation= Mass of blood in circulation X 80/100= 4.2 X 80/100= 3.36 Kg

Mass of blood in arteries of systemic circulation= Mass of blood in systemic circulation X 15/100

                                                                                          = 3.36 X 15/100= 0.504 Kg

2) Pulmonary Mass = Blood Mass x 20/100

(as blood volume is 20/100 of total circulation)

1.3= Blood Mass x 20/100

Blood Mass = 1.3 X 100/20 = 6.5 Kg

a) Mass of this person:

Blood Mass = Body Mass x 7/100

6.5 = Body Mass x 7/100

Body Mass = 6.5 X 100/7= 92.85 Kg= 93 kg

b) Mass of his systemic blood:

Systemic Mass = Blood Mass x 80/100

Systemic Mass = 6.5 x 80/100

Systemic Mass = 5.2 kg