Question

Fill in the blanks:
$a$. Breathing involves two stages: 1 _____ during which atmospheric air is drawn in and 2 _____ expiration by which alveolar air is released 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.

• A. $1$-expiration, $2$-inspiration, $3$-concentration, $4$-lower, $5$-positive, $6$-higher
• B. $1$-inspiration, $2$-expiration, $3$-pressure, $4$- higher, $5$-positive, $6$-lower
• C. $1$-inspiration, $2$-expiration, $3$-pressure, $4$-higher, $5$-negative, $6$-lower
• D. $1$-inspiration, $2$-expiration, $3$-pressure, $4$-lower, $5$-negative, $6$-higher

Answer 1

Answer: (D)

$a$. 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 can 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