Question

Fill up the blanks in the following paragraph by selecting the correct option.
The movement of air into and out of the lungs is carried out by creating a ____(i)____ between the lungs and the atmosphere. Inspiration can occur if intra-pulmonary pressure is ___(ii)____than the atmospheric pressure. Expiration takes place when the intra-pulmonary pressure is ___(iii)___ than the atmospheric pressure. Inspiration is initiated by the ___(iv)___ of diaphragm which ____(v)____ the volume of thoracic chamber in the anteroposterior axis.

• A. (i) concentration gradient (ii) less (iii) higher (iv) relaxation (v)increases
• B. (i) concentration gradient (ii) higher (iii) less (iv) contraction (v)decreases
• C. (i) pressure gradient (ii) higher (iii) less (iv) relaxation (v)decreases
• D. (i) pressure gradient (ii) less (iii) higher (iv) contraction (v) increases

Answer 1

The correct option is D (i) pressure gradient (ii) less (iii) higher (iv) contraction (v) increases

The movement of air into and out of the lungs is carried out by creating an (i) pressure gradient between the lungs and the atmosphere. Inspiration can occur if the intrapulmonary pressure is (ii) less than the atmospheric pressure. Expiration takes place when the intrapulmonary pressure is (iii) higher than the atmospheric pressure. Inspiration is initiated by the (iv) contraction of the diaphragm which (v) increases the volume of the thoracic chamber in the anteroposterior axis.

So, the correct answer is '(i) pressure gradient (ii) less (iii) higher (iv) contraction (v) increases'.