NEETZoologyBreathing and Exchange of Gases
What is the function of spirometer?
Options
- ATo create pressure gradients between the atmosphere and the alveoli
- BTo estimate air volume involved in inspiration and expiration
- CTo utilise oxygen
- DTo produce carbon dioxide
Correct answer
B. To estimate air volume involved in inspiration and expiration
Step-by-step solution
An increase in pulmonary volume decreases the intra-pulmonary pressure to less than the atmospheric pressure which forces the air from outside to move into the lungs, i.e., inspiration Relaxation of the diaphragm and the inter-costal muscles returns the diaphragm and sternum to their normal positions and reduce the thoracic volume and thereby the pulmonary volume. This leads to an increase in intra-pulmonary pressure to slightly above the atmospheric pressure causing the expulsion of air from the lungs, i.e., expir