Inspiration can occur if the intra-pulmonary pressure is _____A______than the atmospheric pressure. Inspiration is initiated by the contraction of diaphragm which increases the volume of thoracic cham

Question

Inspiration can occur if the intra-pulmonary pressure is _____A______than the atmospheric pressure. Inspiration is initiated by the contraction of diaphragm which increases the volume of thoracic chamber in the _____B______axis.

TestHub · Accepted Answer

Mechanism of inspiration:

I. Contraction of diaphragm $\to$ Volume of the thoracic chamber in the antero-posterior axis increases.

II. Contraction of external inter-costal muscles $\to$ Ribs and the sternum are lifted up $\to$ Increase in the volume of the thoracic chamber in the dorso-ventral axis.

III. Increase in the thoracic volume $\to$ Increase in pulmonary volume $\to$ Decrease in the intrapulmonary pressure.

IV. Intra-pulmonary pressure becomes less than the atmospheric pressure. This forces the air from outside to
move into the lungs (inspiration).

Zoology - Breathing and Exchange of Gases Question with Solution | TestHub

Options:

Doubts & Discussion

A	B
More	Antero-posterior

A	B
Less	Antero-posterior

A	B
More	Dorso-ventral

A	B
less	Dorso-ventral