what would be required to extract oxygen and exchange CO2 an

what would be required to extract oxygen and exchange CO2 and how the circulatory would have to change to compensate if humans lived in Extremely dry (very low air humidity) environment?

Solution

To answer this question, we can look at the examples in nature of the organisms that do not have the same complex respiratory systems like we do. If the environment around us gets extremely dry then it would not be possible to get gases through breathing, in that case we can opt for diffusion of gases through our skins, just like in earthworms. the skin should be moist allowing easy diffusion of gases since the atmosphere is very dry.

the circulatory system would change accordingly because whenever the environment is dry it gets either too hot or too cold, whenever the temperature is too cold, the blood vessels would constrict, leading to less blood flow whenever the temperature is very high, the blood vessels would dilate, leading to more blood flow,

the solution to this problem could be an open circulatory system which does not have any blood vessels and the blood is pumped into cavities where tissues are surrounded with blood.