Question

The most important function of diaphragm of the mammals is

• A. To divide the body cavity into compartment
• B. To protect lungs
• C. To aid in ventilation
  
• D. None of the above

Answer 1

Answer: (C)

To aid in ventilation

The diaphragm is a dome-shaped muscular structure. It separates the thoracic and the abdominal region of the body. The main function of the diaphragm is to aid in ventilation. During the process of inspiration and expiration, it contracts and relaxes simultaneously to change the volume of thoracic cavity which creates a pressure difference between the lungs and outer atmosphere which helps to inhale and exhale. During inspiration the diaphragm contracts and increases the volume of the thoracic cavity, and decreases the pressure inside the lungs, thus the air enters inside the lungs. During expiration the diaphragm relaxes and decreases the volume of the thoracic cavity, and increase the pressure inside the lungs, thus the air is forced out of the lungs.

So, the correct answer is 'To aid in ventilation'