Question

Observe the given diagram. Identify the labels $A,B$ and $C$.

• A. A - Air goes inside to lungs, B - Ribs and sternum returned to original position, C - Diaphragm relaxed and arched upward
• B. A - Air goes inside to lungs, B - Ribs and sternum raised, C - Diaphragm contracted
• C. A - Air expelled from lungs, B - Ribs and sternum returned to original position, C - Diaphragm contracted
• D. A - Air expelled from lungs, B - Ribs and sternum raised, C - Diaphragm relaxed and arched upward

Answer 1

Answer: (B)

During inhalation, diaphragm contracts resulting in intake of air which raises the ribs and sternum to compensate the low volume and equalise the pressure with atmospheric pressure.