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 ?
Chest CT (August 30, 2016) demonstrated a mass in posterior mediastinum with moderate pericardial effusion and bilateral pleural effusion [Figure 1]d.
The new ITMG classification system divides the mediastinum into three compartments.
In this study, a rare, mature cystic teratoma that was associated with an anterior intrathoracic meningocele and that developed in the posterior mediastinum is presented.
A case of Mullerian cyst arising in posterior mediastinum.
In this prospective study, we evaluated the role of CT perfusion in differentiation of thymoma from thymic hyperplasia, lymphoma, thymic carcinoma, and invasive lung cancer involving the anterior mediastinum.
The most common type of lesion in the anterior mediastinum was thymic in origin.
Other signs that suggest mediastinal air on the CXR include the 'continuous diaphragm sign' (air trapped posterior to the pericardium), 'Naclerio's V sign', which is formed by the junction of mediastinal air in the left lower mediastinum and extrapleural air adjacent to the left hemidiaphragm, the 'V sign' that is formed by the confluence of the superior margins of the brachiocephalic veins, the 'ring around artery sign' that results from air outlining the pulmonary artery and the main branches, the 'double bronchial wall sign' formed by air outlining the bronchi, air in the pulmonary ligament and irregular bilateral apical extrapleural air.
Previous excision of the smaller lobe with division of bilateral tracheal attachments allows for much greater superior traction on the substernal component of the gland, which facilitates delivery out of the mediastinum and into the neck via blunt finger dissection.
It is defined as the presence of interstitial air in the mediastinum that occurs spontaneously, hence not associated with surgery, trauma, organ rupture, mechanical ventilation, or intrathoracic infection [8].
The surgeon described a dense, fatty, lobulated mass located in the posterior mediastinum with extension into the lower neck and without direct invasion of surrounding structures.
2) The distribution of EHE involving soft tissue as described in a series of 49 cases are extremities (n=32), head and neck (n=6), mediastinum and trunk (n=4, each), genitals (n=2), and the retroperitoneum (n=1).
Mediastinum origin is rare especially with neuroforamen invasion.