Question

During inspiration, muscles of diaphgram

• A. Contracts
• B. Expands
• C. No effect
• D. Coiled like string

Answer 1

The correct option is A Contracts

The diaphragm is the membranous structure in the abdomen. The muscles of the diaphragm contracts during inspiration. Muscle contraction allows the diaphragm to become flat which helps to increase the volume of the thoracic cage. This allows the air to be taken in the lungs. During the process of expiration, the diaphragm becomes dome shaped and the muscles relax. This reduces the volume of the thoracic cage and helps to pump the CO${}_2$ out from the lungs.

Thus, the correct answer is option A.