AskDefine | Define sternum

Dictionary Definition

sternum n : the flat bone that articulates with the clavicles and the first seven pairs of ribs [syn: breastbone] [also: sterna (pl)]

User Contributed Dictionary

English

Etymology

From στέρνον.

Noun

  1. The breastbone.

Derived terms

Translations

  • See under breastbone

See also

Extensive Definition

The sternum (from Greek στέρνον, sternon, "chest" or breastbone) is a long, flat bone located in the center of the thorax (chest). It connects to the rib bones via cartilage, forming the rib cage with them, and thus helps to protect the lungs, heart and major blood vessels from physical trauma.
The sternum is sometimes cut open (a median sternotomy) to gain access to the thoracic contents when performing cardiothoracic surgery.

Overview

, forming the middle portion of the anterior wall of the thorax. Its upper end supports the clavicles (Collar bones), and its margins articulate with the cartilages of the first seven pairs of ribs. Its top is also connected to the Sternocleidomastoid muscle. It consists of three parts, from above downward:
In its natural position, the inclination of the bone is oblique from above, downward and forward. It is slightly convex in front and concave behind; broad above, becoming narrowed at the point where the manubrium joins the body, after which it again widens a little to below the middle of the body, and then narrows to its lower extremity. Its average length in the adult is about 17 cm, and is rather longer in the male than in the female.
In early life its body is divided in four segments, called sternebrœ (singular: sternebra).

Structure

The sternum is composed of highly vascular cancellous tissue, covered by a thin layer of compact bone which is thickest in the manubrium between the articular facets for the clavicles.

Articulations

The sternum articulates on either side with the clavicle and upper seven costal cartilages.

Fractures of the sternum

Fractures of the sternum are rather uncommon. However, they may result from trauma, such as when a driver's chest is forced into the steering column of a car in a car accident. A fracture of the sternum is usually a comminuted fracture, meaning it is broken into pieces. The most common site of sternal fractures is at the sternal angle.
Sternum fractures are frequently associated with underlying injuries such as pulmonary contusions, or bruised lung tissue.

Additional images

References

  • Clinically Oriented Anatomy, 4th ed. Keith L. Moore and Arthur F. Dalley. pp. 66-68.
sternum in Aymara: Tujtuka
sternum in Catalan: Estèrnum
sternum in Danish: Sternum
sternum in German: Brustbein
sternum in Spanish: Esternón
sternum in Esperanto: Sternumo
sternum in French: Sternum
sternum in Croatian: Prsna kost
sternum in Italian: Sterno
sternum in Hebrew: עצם החזה
sternum in Latin: Sternum
sternum in Latvian: Krūšu kauls
sternum in Lithuanian: Krūtinkaulis
sternum in Dutch: Borstbeen
sternum in Japanese: 胸骨
sternum in Norwegian Nynorsk: Brystbein
sternum in Polish: Mostek (anatomia człowieka)
sternum in Portuguese: Esterno
sternum in Slovak: Hrudná kosť
sternum in Slovenian: Prsnica
sternum in Serbian: Стернум
sternum in Finnish: Rintalasta
sternum in Swedish: Bröstben
sternum in Telugu: ఉరోస్థి
sternum in Thai: กระดูกอก
sternum in Turkish: Sternum
sternum in Ukrainian: Грудина
sternum in Chinese: 胸骨
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