Fill in the blanks :
Breathing involves two stages. ...1... dunng vyhlc atmospheric airs drawn in and ...2... explratxon by which alveolar air is relesed out.
b. The movement of air Into and out of the lungs is carried out by ...3... gradient between the lungs and the atmosphere.
c. Inspiration can occur if the pressure within lungs is ...4... than the atmosphere pressure i.e., there is a ...5...pressure in the lungs with respect to atmospheric pressure.
d. Expiration takes place when the intra pulmonary pressure is ...6... than atmospheric pressure.

Options

A. l-expiration, 2-snspiration, 3-concentration, 4-lower, 5-positive, 6-higher
B. l-inspiration, 2-expiration, 3-pressure, 4- higher, 5-positive, 6-lower
C. l-inspiration, 2-expiration, 3-pressure, 4-higher, 5-negative, 6-lower
D. l-inspiration, 2-expiration, 3-pressure, 4-lower, 5-negative, 6-higher

Answer

D

Explanation

a. Breathing involves two stages: inspiration during which atmospheric air is drawn in and expiration by which alveolar air is released out.
b. The movement of air into and out of the lungs is carried out by pressure gradient between the lungs and the atmosphere.
c. Inspiration lcan occur if the pressure within lungs is lower than the atmosphere pressure, i.e. there is a negative pressure in the lungs with respect to atmospheric pressure.
d. Expiration takes place when the intra-pulmonary pressure is higher than atmospheric pressure.