Zoology - Breathing and Exchange of Gases Question with Solution | TestHub
Read the following statements (A – D).
(A) The movement of air into and out of the lungs is carried out by creating a pressure gradient between the lungs and atmosphere.
(B) Inspiration can occur if the pressure within the lungs is more than the atmospheric pressure.
(C) Expiration takes place when the intrapulmonary pressure is lesser than the atmospheric pressure.
(D) The diaphragm and a specialized set of intercostal muscles in between the ribs help in the generation of such pressure gradients for breathing.
How many of the following statements are correct?
Options:
Answer:
Solution:
Statement B and C are wrong, because inspiration can occur if the pressure within the lungs (intra-pulmonary pressure) is less than the atmospheric pressure, i.e., there is a negative pressure in the lungs with respect to atmospheric pressure. Expiration takes place when the intra-pulmonary pressure is higher than the atmospheric Pressure i.e., there is positive pressure in the lungs with respect to atmospheric pressure.
