Gas Exchange

Most terrestrial animals live in environments in which the abundance of gases is relatively constant with oxygen at 21% and CO2 is <0.04%. Yet, many environments are characterized by different gas compositions, including high CO2 and low O2 concentrations in some aquatic environments and low barometric pressures at high altitudes (with gas composition remaining equal to that at sea level). At high altitudes, animals respond by increasing the affinity of hemoglobin and the hematocrit to facilitate the acquisition and transport of oxygen, whereas in stagnant aquatic environments similar changes will occur along with an increased capacity to buffer high levels of environmental CO2. Furthermore, the evolution of a terrestrial from an aquatic habit was associated with a shift from an oxygen-poor environment, due to the limited solubility of oxygen in water, to an oxygen-rich environment. This shift is usually associated with reduced levels of gas exchange, which further enhances life in a terrestrial environment through the reduction in evaporative water loss.

10 Ways To Fight Off Cancer

10 Ways To Fight Off Cancer

Learning About 10 Ways Fight Off Cancer Can Have Amazing Benefits For Your Life The Best Tips On How To Keep This Killer At Bay Discovering that you or a loved one has cancer can be utterly terrifying. All the same, once you comprehend the causes of cancer and learn how to reverse those causes, you or your loved one may have more than a fighting chance of beating out cancer.

Get My Free Ebook


Post a comment