Q. Assertion : The abdominal muscles are primarily involved in generating pressure gradient between the lungs and the atmosphere.
Reason : The strength of inspiration and expiration can be increased by additional muscles in diaphragm and intercostal muscles.

 2198  214 Breathing and Exchange of Gases Report Error

Solution:

The diaphragm and a specialised set of musdesexternal and internal intercostals between the ribs, help in generating pressure gradient. Besides this we can increase the strength of inspiration and expiration with the help of additional muscles in the abdomen.