Short / long answer type questions. Write in brief the mechanism of respiration in mammals.

Answer The process of respiration involves the breathing-in of the oxygen-rich air from outside (inspiration) and breathing-out of the air loaded with carbon dioxide (expiration). During inspiration, the diaphragm moves down and the ribs move upwards and outwards, thereby increasing the space in the chest cavity. This leads to the movement of air inside the lungs. During exhalation, the diaphragm moves to its former position and the ribs move downwards and inwards, thereby reducing the size of the chest cavity. This leads to the movement of air out of the lungs.