Respiratory System in Other Animals

The respiratory system of most animals differs considerably from that of humans. For instance, birds do not possess a diaphragm. They instead boast numerous air sacs which store oxygen-rich and oxygen-deprived air in separate regions. These air sacs open and close rhythmically, flushing out air deprived of useful gases, and sucking in fresh air. This method is much more efficient than that of humans, because it ensures a constant supply of oxygen, rather than an intermittent one. Another example of an animal with a different respiratory system is a fish. They have a specialized structure for respiration know as ‘gills’. Gills consist of many layers of folded tissue, stacked in two lung-shaped adjacent piles. The gill tissue is folded and stacked to increase the surface area of water contacting tissue. This adaptation is in place because water generally has a low oxygen content compared to air, so in order to sustain a large organism, lots of water contacting tissue is required. Many blood vessels are interspersed in the tissue; the oxygen in the water is transferred to the blood through the process of diffusion.