Question

In expiration, diaphragm becomes
(a) flattened (b) relaxed
(c) straightened (d) arched

Answer 1

Answer:

I think ( b ) relaxed is correct

Answer 2

(b) relaxed

Explanation:

When the intra-pulmonary pressure is higher than the atmospheric pressure expiration takes place. In expiration, diaphragm relaxed and the inter costal muscles returns the diaphragm and sternum to their normal positions and reduce the thoracic volume and thereby the pulmonary volumes. This leads to an increase in intra-pulmonary pressure to slightly above the atmospheric pressure causing the expulsion of air from the lungs, i.e., expiration.