The Respiratory System

 The primary function of the respiratory system is the exchange of oxygen, which is needed by the body's cells, for carbon dioxide, which is produced as a waste product of cellular metabolism.

Secondary functions of the respiratory system include voice production, body temperature and acid-base regulation, and the sense of smell.

The structure of the respiratory system consists of the lungs and a complex system of tubes that connects them with the outside world.

The function of the respiratory system depends on some basic physical and body control mechanisms to move air in and out of the lungs, and move oxygen and carbon dioxide in and out of the blood.