TOPOGRAPHY OF THE THORAX AND ABDOMEN 3 1 



from that part of the pleural cavity lying between the heart 

 and the anterior thoracic wall by the adhesions of the me- 

 diastinal and costal pleurae. 



Laterally the heart is in immediate contact with the 

 anterior part of the internal surface of each lung. The 

 right side of the heart may be divided into three areas each 

 of which runs from above downward and forward and cor- 

 responds to one of the three lobes of the right lung. The 

 upper area includes roughly the right auricula, and the conus 

 arteriosus and is in relation with the superior lobe of the 

 lung. The middle area includes the remainder of the right 

 ventricle and the right auricle except the posteroinfe- 

 rior part near the opening of the vena cava inferior. It 

 corresponds to the middle lobe of the lung. The lower 

 area, which corresponds to the inferior lobe of the lung is 

 small and includes a part of each auricle (Plates X, XI and 

 XII). 



The left surface of the heart may be divided in the 

 same way into two areas, which correspond to the two 

 lobes of the left lung. The upper area is the larger and in- 

 cludes the right ventricle, most of the left ventricle, and 

 the superior and anterior part of the left auricle. This 

 area corresponds very closely to the upper and middle 

 areas of the right side. The lower area is a continuation 

 outward of that part of the posterior surface of the heart 

 in relation with the inferior lobe of the left lung. It in- 

 cludes the greater part of the left auricle and the postero- 

 inferior part of the left ventricle. 



The base of the heart is in relation with the great ves- 

 sels which arise from it and with the large mediastinal 

 lymph glands seen in Plate VII. 



The heart is in relation, posteriorly, near the base, 

 with the roots of the lungs. Below the roots of the lungs 



