Mediastinum

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  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 folds of the pleura
     (and the space included between them) which divide the thorax


     into a right and left cavity. The space included between
     these folds of the pleura, called the mediastinal space,
     contains the heart and gives passage to the esophagus and
     great blood vessels.
     [1913 Webster]

From WordNet (r) 2.0 [wn]:

  mediastinum
       n : the part of the thoracic cavity between the lungs that
           contains the heart and aorta and esophagus and trachea
           and thymus
       [also: {mediastina} (pl)]