Respiratory system is very important for the body. Respiration in human beings is divided into two distinct parts. The first part involves taking in oxygen from the air or what we commonly call breathing. The respiratory system is responsible for breathing in and out of air, and exchange of gases. The main parts of the respiratory system consist of the nostrils, trachea or wind pipe and lungs.
The blood, then, transports the oxygen to the individual cell where it is used for the chemical process of respiration. This is known as cellular respiration.The second part involves taking out carbon dioxide, which is a waste product of cellular function.