Question

Identify the CORRECT statement.

Options

• Expiration is initiated due to contraction of diaphragm.

• Expiration occurs due to external intercostal muscles.

• Intrapulmonary pressure is lower than the atmospheric pressure during inspiration.

• Inspiration occurs when atmospheric pressure is less than intrapulmonary pressure.

Answer 1

Intrapulmonary pressure is lower than the atmospheric pressure during inspiration.

Explanation:

The diaphragm contracts, which starts the process of inspiration. The external intercostal muscles flex, raising the ribs and causing more inspiration. When the intrapulmonary pressure is lower than the ambient pressure, inspiration occurs.