Thorax

The thorax is commonly called the chest and the place where many cancers develop, particularly in men. It is the upper half of the body, above the abdomen from which it is separated by the diaphragm muscle. The chest cage is delineated by the ribs and neighbouring muscles, and contains the viscera, principally the lungs, heart and mediastinal organs, which have an essential role in eating (oesophagus), breathing and in circulation.

The thorax, in an insect, is the part of the body lying between the head and abdomen and carrying the three pairs of legs and possibly the wings.