Question

Average Capillary radius is 3um, and average length of a capillary is 0.76mm. The number of capillaries in human boday at one time are 10^10. Estimate the total surface area of all the capillaries available at any one time .

Answer 1

The total surface area of all the capillaries available at any one time is

$$A=N·2\pi r·L=143.3\text{ m}^2.$$