Mediastinum. The division between superior and inferior is at the sternal angle.
Mediastinum anatomy.jpg
Mediastinum anatomy
Gray's subject #239 1090

The mediastinum is a non-delineated group of structures in the thorax, surrounded by loose connective tissue. It is the central compartment of the thoracic cavity. It contains the heart, the great vessels of the heart, esophagus, trachea, phrenic nerve, cardiac nerve, thoracic duct, thymus, and lymph nodes of the central chest.



The mediastinum lies between the right and left pleura in and near the median sagittal plane of the chest. It extends from the sternum in front to the vertebral column behind, and contains all the thoracic viscera except the lungs. It may be divided for purposes of description into two parts:

  • an upper portion, above the upper level of the pericardium, which is named the superior mediastinum with its superior limit at the superior thoracic aperture and its inferior limit at the plane from the sternal angle to the disc of T4-T5 (Plane of Ludwig at Angle of Louis);
  • and a lower portion, below the upper level of the pericardium. This lower portion is again subdivided into three parts, viz.:

It is surrounded by the chest wall anteriorly, the lungs laterally and the spine posteriorly. It is continuous with the loose connective tissue of the neck, and extends inferiorly onto the diaphragm.

Note that clinical radiologists and anatomists categorize the mediastinum in slightly different ways.

Role in disease

The mediastinum is frequently the site of involvement of various tumors.

Mediastinitis is inflammation of the tissues in the mediastinum, usually bacterial and due to rupture of organs in the mediastinum. As the infection can progress very quickly, this is a serious condition.

Pneumomediastinum is the presence of air in the mediastinum, which in some cases can lead to pneumothorax, pneumoperitoneum, and pneumopericardium if left untreated. However, that does not always occur and sometimes those conditions are actually the cause, not the result, of pneumomediastinum. These conditions frequently accompany Boerhaave's syndrome, or spontaneous esophageal rupture.

There are many diseases that can present with a widened mediastinum (usually found via a chest x-ray). The classic is aortic rupture or thoracic vertebrae fracture due to trauma. With infectious etiologies, a widened mediastinum is a classic hallmark sign of anthrax infection.

See also

External links

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Look at other dictionaries:

  • Mediastīnum — (lat.), Mittelfell; daher Media stinītis, Mittelfellentzündung …   Pierer's Universal-Lexikon

  • Mediastīnum — (lat.), Mittelfell, s. Brustfell …   Meyers Großes Konversations-Lexikon

  • Mediastinum — Mediastīnum (lat.), das Mittel , Zwischenfell, das die Brusthöhle in zwei gleiche Teile teilt …   Kleines Konversations-Lexikon

  • Mediastinum —   [neulateinisch, zu lateinisch medius »mittlerer«] das, s/, Anatomie: das Mittelfell.   …   Universal-Lexikon

  • mediastinum — [mē΄dē as tī′nəm] n. pl. mediastina [mē΄dē as tī′nə] [ModL < ML mediastinus, in the middle (form infl. by L mediastinus, servant, medical assistant) < L medius, middle: see MID1] 1. a membranous partition between two cavities of the body,… …   English World dictionary

  • Mediastinum — Organe des Mediastinums Das Mediastinum, deutsch Mittelfell, ist ein senkrecht verlaufender Gewebsraum in der Brusthöhle. Es liegt in der Medianebene zwischen den beiden Pleurahöhlen und reicht vom Zwerchfell bis zum Hals. Das angrenzende… …   Deutsch Wikipedia

  • Mediastinum — The area between the lungs. The organs in this area include the heart and its large veins and arteries, the trachea, the esophagus, the bronchi, and lymph nodes. * * * 1. A septum between two parts of an organ or a cavity. 2. [TA] The median… …   Medical dictionary

  • Mediastinum — Mediastine Me di*as tine, Mediastinum Me di*as*ti num, n. [NL. mediastinum, fr. L. medius middle; cf. mediastinus helper, a menial servant, LL. mediastinus equiv. to medius: cf F. m[ e]diastin.] (Anat.) A partition; a septum; specifically, the… …   The Collaborative International Dictionary of English

  • mediastinum — mediastinal, adj. /mee dee a stuy neuhm/, n., pl. mediastina / a stuy neuh/. Anat. 1. a median septum or partition between two parts of an organ, or paired cavities of the body. 2. the partition separating the right and left thoracic cavities,… …   Universalium

  • Mediastinum — Media|sti̱num [nlat. Bildung zu lat. medius = mittlerer] s; s, 1) „Mittelfell“, Mittelteil des Thoraxinnenraumes, der zwischen den beiden Pleurasäcken liegt und das Herz, die großen Gefäße, die Luftröhre und die Speiseröhre enthält. 2) in… …   Das Wörterbuch medizinischer Fachausdrücke

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