Question

Why is inspiration said to be an active phase and expiration as passive phase?

Answer 1

Answer:

Inspiration occur when muscles of diaphragm contract

during expiration the muscle of diaphragm relax

Answer 2

Answer:

Inspiration and expiration happened in the Lungs through breathing.

Inspiration happens when muscles of the diaphragm contracted this process is called an active process. When muscles of the diaphragm relax expiration happens this is called passive process.

Inspiration and expiration both stand-in simultaneously.

The inspiration process required energy for muscle contraction that's why it is called an active process.

The expiration process does not require energy for muscle relaxation so inside air flows out of the lungs that's why it is a passive process.