Air pressure is highest in the lungs during which of the following points?

select one:
a. beginning of inspiration, when lung volume is lowest
b. beginning of expiration, when lung volume is lowest
c. beginning of expiration, when lung volume is highest

The correct answer is option, A, Beginning of inspiration, when lung volume is lowest

Explanation:

As per the Boyle’s law, Pressure is inversely proportional to Volume as represented by the equation below:

P = k/V  

Where, P = Pressure  

V = Volume  

k = gas constant

Thus if the volume is low, pressure will be the highest.

At the initial stage of respiration, the lung is required to inhale maximum oxygen. The maximum oxygen can be inhaled when the pressure is highest and this happens only when the volume of lung is lowest.