MHT CET Medical202624 April 2026Morning ShiftBiologyBreathing and Exchange of GasesActual
Which of the following statements are correct? (A) Intrathoracic pressure decreases during inspiration. (B) Activation of pneumotaxic center stimulates inspiration. (C) During expiration, pressure gradient operates from lungs to the atmosphere. (D) Cavity of lungs decreases during expiration. (E) Diaphragm contracts during expiration. Select the correct option
Options
- AC, D and E only
- BA and B only
- CA, C and D only
- DD and E only
Correct answer
C. A, C and D only
Step-by-step solution
Statement (A) is correct because during inspiration, the volume of the thoracic cavity increases, which leads to a decrease in intrathoracic pressure, allowing air to rush into the lungs. Statement (B) is incorrect because the pneumotaxic center, located in the pons, sends inhibitory signals to the inspiratory center, thereby limiting inspiration and increasing the respiratory rate. Statement (C) is correct because during expiration, the intrapulmonary pressure becomes higher than the atmospheric pressure, creating