mediastinum


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mediastinum

 [me″de-ah-sti´num] (L.)
1. a median septum or partition.
2. the mass of tissues and organs separating the sternum in front and the vertebral column behind, containing the heart and its large vessels, trachea, esophagus, thymus, lymph nodes, and other structures and tissues. It is divided into anterior, middle, posterior, and superior regions.
mediastinum tes´tis a partial septum of the testis formed near its posterior border by a continuation of the tunica albuginea.

me·di·as·ti·num

(me'dē-as-tī'nŭm),
1. A septum between two parts of an organ or a cavity.
2. The median partition of the thoracic cavity, covered by the mediastinal part of the parietal pleura and containing all the thoracic viscera and structures except the lungs. It is divided arbitrarily into two major divisions: the superior mediastinum [TA] (mediastinum superus [TA]), which lies directly superior to a horizontal plane intersecting the sternal angle and approximately the T4-5 intervertebral disc, and the inferior mediastinum [TA] (mediastinum inferius [TA]) inferior to that plane; the latter is, in turn, subdivided in three parts: a middle mediastinum [TA] (mediastinum medium [TA]), which is coterminus with the pericardial sac containing the heart: a nearly potential anterior mediastinum [TA] (mediastinum anterius [TA]) lying in front: and a posterior mediastinum [TA] (mediastinum posterius [TA]) behind, containing the esophagus, descending aorta, and thoracic duct. Synonym(s): interpleural space, interpulmonary septum, mediastinal space, septum mediastinale
[Mod. L. a middle septum, fr. Mediev. L. mediastinus, medial, fr. L. mediastinus, a lower servant, fr. medius, middle]

mediastinum

/me·di·as·ti·num/ (me″de-ah-sti´num) pl. mediasti´na   [L.]
1. a median septum or partition.
2. the mass of tissues and organs separating the two pleural sacs, between the sternum in front and the vertebral column behind, containing the heart and its large vessels, trachea, esophagus, thymus, lymph nodes, and other structures and tissues; it is divided into superior and inferior regions, the latter subdivided into anterior, middle, and posterior parts.
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Subdivisions of the mediastinum.

mediastinum tes´tis  the partial septum of the testis, formed near its posterior border by a continuation of the tunica albuginea.

mediastinum

(mē′dē-ə-stī′nəm)
n. pl. mediasti·na (-nə)
The region in mammals between the pleural sacs, containing the heart and all of the thoracic viscera except the lungs.

me′di·as·ti′nal (-nəl) adj.

mediastinum

[mē′dē·əstī′nəm] pl. mediastina
Etymology: L, mediastinus, midway
a part of the thoracic cavity in the middle of the thorax, between the pleural sacs containing the two lungs. It extends from the sternum to the vertebral column and contains all the thoracic viscera except the lungs. It is enclosed in a thick extension of the thoracic subserous fascia and is divided into the anterior mediastinum, middle mediastinum, posterior mediastinum, and superior mediastinum. mediastinal, adj.
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Mediastinum

mediastinum

The region of the thorax bounded by the lungs, which includes the heart and regional vessels, trachea, oesophagus, bronchi, lymph nodes.

Mediastinal regions: Tissues and tumours
• Superior: Lymphoid, thymic, thyroid, parathyroid.
• Anterior: Thymic, germ cell, lymphoid, thyroid, parathyroid.
• Middle: Trachea and main bronchi (bronchogenic cyst), pericardial, lymphoid.
• Posterior: Sympathetic ganglia, paraganglia (neurogenic tumours), lymphoid, oesophageal, vascular.

me·di·as·ti·num

(me'dē-ă-stī'nŭm) [TA]
1. A septum between two parts of an organ or a cavity.
2. The median partition of the thoracic cavity, covered by the mediastinal part of the parietal pleura and containing all the thoracic viscera and structures except the lungs. It is divided arbitrarily into two major divisions: a superior mediastinum (mediastinum superius [TA]), which lies directly superior to a horizontal plane intersecting the sternal angle and approximately the T4-5 intervertebral disc, and an inferior mediastinum (mediastinum inferius [TA]) inferior to that plane; the latter is, in turn, subdivided in three parts: a middle mediastinum (mediastinum medium [TA]), which is coterminous with the pericardial sac containing the heart, a nearly potential anterior mediastinum (mediastinum anterius [TA]) lying in front, and a posterior mediastinum (mediastinum posterius [TA]) behind, containing the esophagus, descending aorta, and thoracic duct.
Synonym(s): interpleural space, mediastinal space.

mediastinum

The central compartment of the chest, flanked on either side by the lungs, and containing the heart, the origins of the great blood vessels, the TRACHEA and the main BRONCHI, the OESOPHAGUS and many lymph nodes.

mediastinum

the space in the chest of mammals containing the HEART, TRACHEA and OESOPHAGUS.

Mediastinum

The area between the lungs, bounded by the spine, breastbone, and diaphragm.
Mentioned in: Lung Biopsy, Pneumothorax

me·di·as·ti·num

(me'dē-ă-stī'nŭm) [TA]
1. A septum between two parts of an organ or a cavity.
2. The median partition of the thoracic cavity, covered by the mediastinal part of the parietal pleura and containing all the thoracic viscera and structures except the lungs.

mediastinum

(mē´dēas´tənī´nəm),
n a portion of the thoracic cavity in the middle of the thorax between the pleural sacs containing the two lungs. It extends from the sternum to the vertebral column and contains all the thoracic viscera except the lungs.

mediastinum

pl. mediastina [L.]
1. a median septum or partition.
2. the mass of tissues and organs separating the two lungs, between the sternum ventrally and the vertebral column dorsally, containing the heart and its large vessels, trachea, esophagus, thymus, lymph nodes, and other structures and tissues. In the horse, the caudal part of the mediastinum is usually fenestrated and the two pleural cavities communicate with each other through it.
References in periodicals archive ?
On the follow-up graphy taken 4 weeks later enlargment in the mediastinum was observed to be regressed.
2) Those lesions were also the apparent basis for hemorrhagic lesions in the meninges, gastrointestinal submucosa, and mediastinum.
Malagon and colleagues reported one case of rhabdomyosarcoma associated with a YST of the mediastinum, but not of the testis.
The patient received 3-dimensional conformal external beam radiotherapy (3D-CRT) to the mediastinum (46.
The Chest CT scanner showed markedly enlarged lymphnodes in the mediastinum and hili.
This had drained into the mediastinum and into the right chest.
This atlas-based text intended for both residents and seasoned practitioners in need of up-to-date information covers every anatomic region in detail--skin, head and neck, lung and mediastinum, endocrine system, digestive system genitourinary system, breast and female genitals, hematopoietic tumors, soft tissue and bone, central nervous system, and metastic carcinoma of unknown primary.
The researchers used the heart/mediastinum ratio (H/M) to assess the functionality of the sympathetic nerves; H/M is a ratio of the nerve function in the heart compared to that of a reference background region in the mediastinum (the mass of tissues and organs between the two pleural sacs, which separate the heart from the lungs).
The complexity of the structures in the chest including the ribs, mediastinum and pulmonary vessels can make it difficult to identify separate pulmonary nodules that may represent an early lung cancer from normal anatomy.
A possible explanation for the unexpected finding in our patient may be the unusual growth pattern of the thymus, from the mediastinum towards the cervical area.
A contrast-enhanced computed tomographic (CT) scan of the neck and chest showed cervical subcutaneous emphysema, pneumomediastinum, and multiple pockets of accumulated turbid fluid over the neck, superior mediastinum, and bilateral pleural spaces (Fig.