THORAX 



lungs : (i) The right lung is slightly larger than the left, in 

 the proportion of n to 10. (2) The right lung is shorter 

 and wider than the left lung. This difference is due to 

 the great bulk of the right lobe of the liver, which elevates 

 the right cupola of the diaphragm to a higher level than 

 the left cupola, and also to the heart and pericardium, which 

 project more to the left than the right, and thus diminish 

 the width of the left lung. (3) The anterior sharp 

 margin of the right lung is more or less straight; the 

 corresponding margin of the left lung presents, in its lower 

 part, a marked angular* deficiency (incisura cardiaca) for the 



Reflection 

 of pleura 



Bronchial _il 

 gland A 



Pulmonary 

 veins 



_^ Pulmonary 

 veins 



Ligamentum pulmonis 



FIG. 1 8. The two Pulmonary Roots transversely divided close to the 

 hilus of each lung. 



reception of the heart and the pericardium. (4) The right 

 lung is subdivided into three lobes, and the left lung into two. 

 Radix Pulmonis. The root of the lung is formed by a 

 number of structures which enter the lung at the hilus or 

 slit on its mediastinal surface. The structures which form 

 the root are held together by an investment of pleura, and 

 they constitute a pedicle which attaches the lung to the 

 contents of the mediastinum. The pleura has already been 

 removed from around them, and now a more detailed 

 examination of the constituent parts of the root and of its 

 relations must be made. The portion of the root still 



