When do inspiration and expiration take place?

When do the expiratory muscles contract?

What is the difference between pulmonary respiration in frogs and human respiration?

Arrange the given steps by which the lungs show inspiration,in the sequence of events occurring first:
$I.$ Increase in the volume of the thoracic chamber in the dorsoventral axis
$II.$ Upward and outward movement of the ribs
$III.$ Contraction of intercostal muscles
$IV.$ Entry of air inside the lungs
$V.$ Contraction of the diaphragm
$VI.$ Increase in the volume of the thoracic chamber in the anteroposterior axis
Choose the correct option.

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

Select the incorrect option for the given diagram (representing inspiration).