Question

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. The pulmonary blood volume per area is 271 ml/m2. Capillary blood volume varies between 20% and 25% of the pulmonary blood volume.

1. a) Assuming capillaries are 8 um in diameter and have an average length of 1 mm, calculate the range of the number of open capillaries in the lung during rest for a child of 10 years of age, an adult woman, and an adult man during rest.

   [13 marks]

2. b) After exercise the pulmonary blood volume doubles due to vasodilation, and there is capillary recruitment of 100%. Calculate the number of capillaries perfused in the lungs during exercise. Justify your answer.

   [6 marks]

3. c) What can you conclude from these estimates?

   [6 marks]

Answer 1

Ans Normally the pulmonary capillaries have the diameter of 6m we are assuming 8m in diameter which greater than the average diameter of pulmonary capillaries and average length is of 600microns now the conditon is that if there is flow of blood through 8m and average length of 1mm blood flow is not flow properly as compare to normal pulmonary blood flow because of diameter is larger than the average as compare to boy capillary surface area is 1.14m2 and normal surface area is 800 to 900m2 which is larger than 6 times thats why proper flow is not through this condition

same condition also applicable for women and adult man because of normal area is 800 to 900 m2

after during exercise the pulmonary blood flow of volume is more because heart pump blood during stenous exercise and during exercise tidal volume of lung increases and depth of breathing also increases

conclusion is from above that during exercise pulmonary blood volume and breathing also increase because at this time heart pump more blood and lung circulate this blood to organs