Question

Observe the picture given below depicting an activity performed to study action of certain part of human respiratory system. Identify and explain the action of the part in brief.

Answer 1

The activity is performed to study the action of diaphragm in breathing.

• At the time of inspiration, the diaphragm contracts, increasing the pulmonary volume thereby reducing the pressure inside less than the atmospheric pressure and air moves into the lungs.
• At the time of expiration, the diaphragm relaxes, reducing the pulmonary volume and thereby increasing the pressure inside lungs slightly more than the atmospheric pressure. This leads to the expulsion of air from the lungs.