ZOO 303- Respiration

The human respiratory system is a series of organs that takes in oxygen and expel carbon di oxides, primary organs, lungs which carries out exchange of gases as we breathe. Red blood cells collects the oxygen from this lungs carry it to the other part of the body, collects carbon di oxide and transport it back to the lungs. Carbon di oxide is what we exhale. Human body needs oxygen to sustain itself. Decrease in oxygen is known as hypoxia.