ABSTRACT
This readily palpable protuberance is an important landmark: here the 2nd costal cartilage articulates on the same plane as the 4th thoracic vertebra, the bifurcation of the trachea, and the beginning and end of the aortic arch. The body of the sternum is some 10 cm long and articulates
on its lateral borders with the 2nd to the 7th costal cartilages. Behind the body lie the heart valves, in the order from above downwards PAMT (pulmonary, aortic, mitral and tricuspid: see Fig. 2.1b, p. 35). The narrow lower end articulates with the xiphoid cartilage, which is cartilaginous in early life and gives attachment to the diaphragm and rectus abdominis.
