Question

In mammals, the efficiency of ventilation of lungs as compared to reptiles and birds is better developed due to the presence of:

• A. Ribs and costal muscles
• B. Only ribs
• C. Only costal muscles
• D. Diaphragm

Answer 1

The correct option is D Diaphragm

In mammals like humans, inspiration and expiration are carried out by creating pressure gradients between the atmosphere and the alveoli with the help of specialised muscles - intercostals and diaphragm. The diaphragm is a dome-shaped muscular separation between abdominal and thoracic cavities. It is characteristic of mammals. It increases the efficiency of ventilation in mammals.

Hence the correct option is D.