|—n , pl thoraxes, thoraces|
|1.||the part of the human body enclosed by the ribs|
|2.||the corresponding part in other vertebrates|
|3.||the part of an insect's body between the head and abdomen, which bears the wings and legs|
|[C16: via Latin from Greek thōrax breastplate, chest]|
|either of two bones of the skull of vertebrates above the fishes that lie in front of frontal bones|
|SMALLEST BONE IN THE BODY|
thorax tho·rax (thôr'āks')
n. pl. tho·rax·es or tho·ra·ces (thôr'ə-sēz')
The part of the human body between the neck and the diaphragm, partially encased by the ribs and containing the heart and lungs; the chest.
A part in other vertebrates that corresponds to the human thorax.
The second or middle region of the body of an arthropod, between the head and the abdomen, in insects bearing the legs and wings.
|thorax (thôr'āks') Pronunciation Key
Plural thoraxes or thoraces (thôr'ə-sēz')
The part of the body between the neck and diaphragm; the chest.
in amphibians, reptiles, birds, and mammals, the chest. In humans and other mammals the chest is that part of the body between the neck and abdomen. In humans the bony framework of the thorax consists of the 12 thoracic vertebrae, 12 pairs of ribs, and the sternum (breastbone). The mammalian thorax contains the chief organs of respiration and circulation, namely, the lungs, some air passages, the heart, and the great vessels (see thoracic cavity). Below, it is bounded by the diaphragm. The bony framework is encased with muscles, fat, and cutaneous tissues.
Learn more about thorax with a free trial on Britannica.com.