In this article we will discuss about the structure of the respiratory organs in human body with the help of a suitable diagram.
A pair of lungs lies in the airtight thoracic (‘chest’) cavity, as shown in fig 45.
During breathing, the lungs are inflated and deflated by the action of muscles which help to form the thorax.
They are:
(i) The intercostal muscles (between the ribs)
(ii) The muscles of the diaphragm. The diaphragm is a sheet of muscle lying below the lungs, separating them from the abdomen. It is curved upwards (towards the lungs) like a dome.
These muscles work to alter the volume of the thoracic cavity, which, in turn, alters the pressure within the thoracic cavity.
