Question

Read the given statements. How many of them are correct?

a. Diaphragm contracts during inspiration.

b. Relaxation of external intercostal muscles lifts sternum upwards & outwards.

c. Partial pressure of O2 in atmospheric air is higher than that in the alveoli, so O2 diffuses from atmospheric air into alveoli

d. During forceful expiration, abdominal muscles contract.

e. Inspiration in mammals is a passive process

Choose answer:

1.One


2.Two


3.Three


4.Four

Answer 1

all are correct............................................

Answer 2

The 4.Four statements mentioned in options are correct.

The statements mentioned in question are the steps of respiration. Respiration refers to exchange of gases between environment and body.

The oxygen is taken in, referred to as inhalation. The carbon dioxide is released out, referred to as exhalation. The primary organ involved in the process is lungs.

The incorrect statement is - Inspiration in mammals is a passive process.

The reverse is true, as inhalation is active process while exhalation is passive process.

This is so, because contraction of muscles takes place during inhalation which requires energy.

While relaxation of muscles does not require energy, hence making it passive process.