Question 4
The capillary surface area of a child 10 years old is 1.14 m2,of an adult woman is 1.6 m2, and of an adult, man is 1.9 m2. Thepulmonary blood volume per area is 271 ml/m2. Capillary bloodvolume varies between 20% and 25% of the pulmonary bloodvolume.
a) Assuming capillaries are 8 um in diameter and have an averagelength of 1 mm, calculate the range of the number of opencapillaries in the lung during rest for a child of 10 years of age,an adult woman, and an adult man during rest.
[13 marks]
b) After exercise the pulmonary blood volume doubles due tovasodilation, and there is capillary recruitment of 100%. Calculatethe number of capillaries perfused in the lungs during exercise.Justify your answer.
[6 marks]
c) What can you conclude from these estimates?
[6 marks]
