[mee-dee-a-stahy-nuh
m] 
[-a-stahy-nuh] . Anatomy. | 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, formed of the two inner pleural walls, and, in humans, comprising all the viscera of the thorax except the lungs. |
| me·di·as·ti·num (mē'dē-ə-stī'nəm) n. pl. me·di·as·ti·na (-nə) The region in mammals between the pleural sacs, containing the heart and all of the thoracic viscera except the lungs. [New Latin mediastīnum, from neuter of Medieval Latin mediastīnus, medial, from Latin, inferior servant, drudge (anatomical sense probably influenced by Latin intestīnum, intestine), from medius, middle; see medhyo- in Indo-European roots.] me'di·as·ti'nal (-nəl) adj. |
mediastinum me·di·as·ti·num (mē'dē-ə-stī'nəm)
n. pl. me·di·as·ti·na (-nə)
A septum between two parts of an organ or a cavity.
The region in mammals between the pleural sacs, containing the heart and all of the thoracic viscera except the lungs. Also called interpleural space, mediastinal space.
mediastinum
the anatomic region located between the lungs that contains all the principal tissues and organs of the chest except the lungs. It extends from the sternum, or breastbone, back to the vertebral column and is bounded laterally by the pericardium, the membrane enclosing the heart, and the mediastinal pleurae, membranes that are continuous with those lining the thoracic cage. The mediastinum is a division of the thoracic cavity; it contains the heart, thymus gland, portions of the esophagus and trachea, and other structures. For clinical purposes it is traditionally divided into the anterior, middle, posterior, and superior regions
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