On an average,a healthy human breathes $......$ times per minute.

Explain the mechanism of expiration.

Volume of thoracic chamber increases in antero-posterior and dorso-ventral axis in rabbit by

If there is a puncture in the thoracic cavity but not in the lungs,then...

In a minute, a normal healthy human adult respires: (in $\times$)

Select the correct process that occurs during inspiration (inhalation):
$(a)$ Contraction of the diaphragm
$(b)$ Contraction of external intercostal muscles
$(c)$ Decrease in pulmonary volume
$(d)$ Increase in intra-pulmonary pressure