The Importance of Oxygen in AnimalsOxygen is an element needed to sustain all life on earth. But why? Well, in order to the process of cellular respiration to occur, oxygen is needed. Cellular respiration gives energy to the cells so they can carry out necessary life functions. In the mitochondria, glucose and oxygen combine to produce carbon dioxide, water and ATP, which is the energy the body needs*. In addition to being needed for cellular respiration, oxygen is also used rid the blood of carbon dioxide.
*cellular respiration formula: C6H12+O2→ CO2 + H2O + Energy |
Diagram of the Mitochondria |
Gas Exchange in Birds
The avian respiratory system is very different from that of mammals. In mammals the diffusion of oxygen occurs in one organ inside the lungs. "Clean" air, or air with oxygen is taken in through the nasal cavity, through movement in the diaphragm, and is taken to the lungs and diffused into the blood stream from the aveoli in the lungs, and the "dirty" air or air with carbon dioxide is pushed into the lungs and exhaled. But in birds these processes of gas exchange and ventilation happen in two different organs. They have relatively small lungs so that the organs needed for both gas exchange and ventilation can function in such a small space. The lungs preform the gas exchange and nine different air sacs within the body preform ventilation. There is one interclavicular sac, two cervical sacs, two anterior thoracic sacs, two posterior thoracic sacs, and two abdominal sacs. These air sacs also help to lighten the weight of the bird which aids in flight. The air sacs also create a one way air flow in the bird. In humans there is a two way air flow which mixes "good" air and "bad" air. This one way air flow allows the oxygen rich air to diffuse more quickly into the blood stream to give more energy faster. Birds have four sets of bronchi to regulate air flow: Dorsobronchi, ventrobronchi, parabronchi, and dorsobronchi. They each bring oxygenated blood from each of the air sacs and maintain the one way air flow. Birds use up a lot of energy while flying and hunting which is why their respiratory system is designed to be efficient and fast acting.