MarksRiser
MarksRiser
Zoology-Respiratory Organs

NEET Zoology Respiratory Organs MCQ Question

Type: MCQ-conceptual-Medium-Class 11

If the diaphragm relaxes and the inter-costal muscles return to their normal positions, how does this affect the intra-pulmonary pressure compared to atmospheric pressure?

A

It becomes slightly higher than atmospheric pressure.

B

It becomes equal to atmospheric pressure.

C

It remains the same as before relaxation.

D

It becomes slightly lower than atmospheric pressure.

Correct Answer

Option A

Detailed Explanation

As the diaphragm and inter-costal muscles relax, the thoracic volume decreases, increasing intra-pulmonary pressure slightly above atmospheric pressure, causing expiration.

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