Subdivisions of the Thoracic Cavity

In preparation for studying the internal organs of the thoracic cavity, we will subdivide it artificially into several parts. It is thought that doing this will aid memorizing what is located in each subdivision. First, when looking at a cross section, we can subdivide the cavity into left and right pleural cavities and an intermediate area called the mediastinum.
Subdivisions of thorax
as seen on cross section
  • left and right pleural cavities
  • mediastinum
subdivision of thoracic cavity

Subdivision of the Mediastinum According to Anatomists

Subdivision of mediastinum
as seen on cross section
  • anterior mediastinum (1)
  • middle mediastinum (2)
  • posterior mediastinum (3)
subdivision of mediastinum on cross section
Subdivision of mediastinum
as seen on sagittal section
  • superior mediastinum (1)
  • anterior mediastinum (2)
  • medial mediastinum (3)
  • posterior mediastinum (4)
subdivision of mediastinum on sagittal section

Boundaries of the mediastinum

subdivision of mediastinum on sagittal section

Subdivision of the Mediastinum According to Some Clinical Radiologists

Clinical radiologists have described the subdivisions of the mediastinum in the following way:
  • the anterior mediastinum by the clinician is the anterior and middle mediastina combined and it extends into the superior mediastinum anterior to the plane of the anterior surface of the trachea.
  • the middle mediastinum includes the posterior mediastinum and the part of the superior mediastinum posterior to a plane anterior to the trachea
  • the posterior mediastinum includes the bodies of the vertebrae which includes the paravertebral space and thus includes the sympathetic chains on each side. This is the region that neurogenic tumors might occur.
subdivision of mediastinum according to clinicians
Pleural Cavity   Heart


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