Sternum

Anatomic name for the breast bone, the long flat bone in the upper middle of the front of the chest. The sternum articulates (comes together) with the cartilages of the first seven ribs and with the clavicle (collar bone) on either side. The sternum consists of three parts: the manubrium (the upper segment of the sternum, a flattened, roughly triangular bone), the corpus or body of the sternum, and the xiphoid process (the little tail of the sternum than points down). These sections of the sternum arise as separate bones and later they may fuse partially or completely with one another. The word "sternum" comes from the Greek "sternon" meaning "the breast or chest." The word "sternum" was once used to refer to the chest but this use was supplanted by the "thorax" and the sternum became the name of the familiar flat bone in the middle of the front of the chest.

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A long flat bone, articulating with the cartilages of the first seven ribs and with the clavicle, forming the middle part of the anterior wall of the thorax; it consists of three portions: the corpus or body, the manubrium, and the xiphoid process. SYN: breast bone. [Mod. L. fr. G. sternon, the chest]

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ster·num 'stər-nəm n, pl -nums or -na -nə a compound ventral bone or cartilage that lies in the median central part of the body of most vertebrates above fishes and that in humans is about seven inches (18 centimeters) long, consists in the adult of three parts, and connects with the clavicles and the cartilages of the upper seven pairs of ribs called also breastbone

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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 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.

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ster·num (sturґnəm) [L., from Gr. sternon] [TA] a longitudinal unpaired plate of bone forming the middle of the anterior wall of the thorax; it articulates above with the clavicles and along its sides with the cartilages of the first seven ribs. Its three parts are the manubrium, the body (corpus sterni), and the xiphoid process (processus xiphoideus). sternal adj

Sternum. (A), Anterior view; (B), posterior view.