THE MEDIASTINUM, OR INTERPLEURAL SPACE 



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it, the bifurcation of the trachea and the two bronchi, the pulmonary artery divid- 

 ing into its two branches and the right and left pulmonary veins, the phrenic 

 nerves, and some bronchial lymph nodes. 



The posterior mediastinum (Figs. 897 and 902) is an irregular triangular space 

 running parallel with the vertebral column; it is bounded in front by the peri- 



FIG. 902. The posterior mediastinum. 



cardium above, and by the posterior surface of the Diaphragm below, behind 

 by the vertebral column from the lower border of the fourth to the twelfth thoracic 

 vertebra, and on either side by the pleura. It contains the descending thoracic 

 aorta, the venae azygos major and minor, the vagus and splanchnic nerves, the 

 oesophagus, the thoracic duct, and some lymph nodes. 



