thorax /thôr′aks/ pl. thoraxes, thoraces [Gk, chest] , the upper part of the trunk or cage of bone and cartilage containing the principal organs of respiration and circulation and covering part of the abdominal organs. It is formed ventrally by the sternum and costal cartilages and dorsally by the 12 thoracic vertebrae and the dorsal parts of the 12 ribs. The thorax of women has less capacity, a shorter sternum, and more movable upper ribs than that of men. Also called chest. −thoracic, adj.
