Question

During inspiration, the diaphragm

• A. expands
• B. shows no change
• C. contracts and flattens
• D. relaxes to become dome-shaped

Answer 1

Answer: (C)

contracts and flattens

Answer 2

During inspiration, the diaphragmcontracts and then flatten to increase the thoracic cavity volume.

• The increase in volume leads to a decrease in intra-alveolar pressure.
• Intra-alveolar pressure is a pressure lower than atmospheric pressure that creates a pressure gradient.
• Due to the gradient, the air from the atmosphere is forced inside the lungs through the nasal cavity.

Breathing refers to the periodically filling of the lung with atmospheric air and then emptying it. Breathingin is known as inhalation or inspiration while breathing out is known as exhalation or expiration. During inhalation, the diaphragm contracts by partial flattening and increases the thoracic cavity lengthwise.

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