NEETZoologyBreathing and Exchange of Gases
To expel the Expiratory Reserve Volume (ERV) from the lungs, a person must perform a forcible expiration. Which of the following muscular events is required to achieve this?
Options
- AContraction of additional muscles in the abdomen
- BRelaxation of the diaphragm and external inter-costal muscles only
- CContraction of the diaphragm and external inter-costal muscles
- DRelaxation of the abdominal muscles along with contraction of the diaphragm
Correct answer
A. Contraction of additional muscles in the abdomen
Step-by-step solution
Expiratory Reserve Volume (ERV) is defined as the additional volume of air a person can expire by a forcible expiration. Normal expiration is a passive process that occurs due to the relaxation of the diaphragm and external inter-costal muscles. However, to perform a forcible expiration and expel the ERV, active muscle contraction is required. Humans have the ability to increase the strength of expiration with the help of additional muscles in the abdomen. Therefore, the contraction of abdominal muscles facilitates