The Respiratory System

Respiration* is a physical process by which living organisms inhale oxygen from the surrounding atmosphere and then exhale carbon dioxide. The respiratory system is made up of organs that deliver oxygen to the circulatory system for transport to the cells in the animal’s body. The most critical requirement of life support to an animal is oxygen. An animal may be able to survive several weeks without food or several days without water, but when it comes to trying to survive without oxygen, the period is measured in several minutes. The major functions of the respiratory system are providing oxygen to tissues and cells and removing carbon dioxide from the body. Other important functions include controlling body temperature, eliminating water (as vapor), and aiding in voice production. The respiratory system of animals includes the lungs and the passages that provide transportation of air into the lungs. These passages include the nostrils, nasal cavity (chamber), pharynx, larynx, trachea, and bronchial tubes.