Question

During inspiration, the diaphragm

• A. Expands
• B. Shows no change
• C. Contracts and flattens
• D. Relaxed to become dome shaped

Answer 1

Answer: (C)

Contracts and flattens

During inspiration, the diaphragm contracts and flattens to increase the volume of the the thoracic cavity. This increase in volume leads to a decrease in intra-alveolar pressure, which is a pressure lower than atmospheric pressure and creates the pressure gradient. Due to the gradient the air is from the atmosphere is forced inside the lungs through nasal cavity.

So, the correct answer is 'Contracts and flattens'.