n. (pl. sterna) the breastbone: a flat bone, 15–20 cm long, extending from the base of the neck to just below the diaphragm and forming the front part of the skeleton of the thorax. The sternum articulates with the collar bones (see clavicle) and the costal cartilages of the first seven pairs of ribs. It consists of three sections: the middle and longest section – the body or gladiolus – is attached to the *manubrium at the top and the *xiphoid (or ensiform) process at the bottom. The manubrium slopes back from the body so that the junction between the two parts forms an angle (angle of Louis or sternal angle). —sternal adj.... sternum
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