950 



A MANUAL OF ANATOMY 



The upper lobe is comparatively small, and includes the apex, 

 about the upper 3 inches of the posterior border, the anterior 

 border, and, in the case of the left lung, practically all that can be 

 auscultated anteriorly. The lower lobe is of large size, and lies 

 behind and below the great pulmonary fissure. It includes 

 the base, the posterior border except the upper 3 inches, and prac- 

 tically all that can be auscultated posteriorly. 



By means of the great pulmonary fissure each lung, as stated, is 

 divided into two iooes. In the case of the left lung the division 

 proceeds no further. In the case of the right lung, however, there 

 is an additional fissure, which extends from the chief fissure, at 



Right Bronchus 



Right 

 Pulmonary^ 

 Artery *^^ 



Right 

 Pulmonary ,.-,-,^.\ , 

 Veins ^^§{t\) . 



Left Pulmonary Artery 



Left Bronchus 



Fig. 389. — The Roots of the Lungs (Anterior View). 



the posterior border, horizontally forwards over the outer surface 

 to the anterior border at about the level of the lower margin of 

 the fourth right costal cartilage, which corresponds to the com- 

 mencement of the cardiac notch on the anterior border of the left 

 lung. This additional fissure cuts off from the upper lobe a tri- 

 angular or wedge-shaped portion, which is called the middle 

 lobe. 



Differences between the two lungs — (i) The right lung has two 

 fissures and three lobes, whilst the left lung has only one fissure 

 and two lobes. (2) The anterior border of the right lung is unin 

 terrupted, whilst that of the left lung presents interiorly the cardia 



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