Q.
In the given diagram, identify what is depicted by $A,B$ and $C$ Choose the correct option
A) A-Air going out from lungs, B-Ribs and sternum relaxed, C-Volume of thorax increased
B) A-Air entering lungs, B-Ribs and sternum relaxed, C-Volume of thorax increased
C) A-Air entering lungs, B-Ribs and sternum raised, C-Volume of thorax increased
D) A-Air going out from lungs, B-Ribs and sternum relaxed, C-Volume of thorax decreased
Explanation
A – Air entering lungs B – Ribs and sternum raised C – Volume of thorax increased Pulmonary volume increases by the following steps (i) Contraction of the diaphragm (ii) Contraction of intercostal muscle (iii) Lifting of the ribs (iv) Sternum causing an increase in the volume of thoracic chamber in dorso ventral axis [image:17_image25.png]
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.