THORAX 



will find that the inferior or diaphragmatic surface, which 

 rests upon the diaphragm, is slightly concave; that it is 

 formed entirely by the ventricles, and mainly by the left 

 ventricle, which forms the left two -thirds, the separation 

 between the ventricles being indicated by the inferior longi- 

 tudinal sulcus. As the apex of the heart is held upwards 

 and to the right, the dissector should note that a recess of 



Innominate artery 



Aortic arch 

 Pulmonary artery 



Pulmonary val 

 Conus arteriosus 

 Pericardial cavity 

 Ascendinglaorta 



Aortic valve 

 Aortic sinus 



Left common carotid 



Superior vena cava 



Vena azygos 

 Right 

 --pulmonary artery 



Right pulmonary 

 ' artery 



Transverse sinus 

 of pericardium 

 Oblique sinus 

 of pericardium 

 Upper right 

 pulmonary vein 

 Left atrium 



Lower left 

 pulmonary vein 



Base of anterior cusp 

 of mitral valve 

 Oblique sinus of pericardiur 

 Coronary sinus 



FIG. 27. Sagittal Section of Heart. 



the pericardial cavity ascends posterior to the base or posterior 

 surface of the heart. This recess is the oblique sinus of the 

 pericardium. Its orifice is below, where it is bounded to 

 the right and below by the upper end of the inferior vena 

 cava, and to the left and above by the left inferior pulmonary 

 vein. The posterior boundary of the sinus is the pericardium; 

 and the pericardium separates the cavity of the sinus from 

 the oesophagus, which, at this level, is lying between the 

 pericardium and the descending part of the thoracic portion 

 of the aorta. Both the oesophagus and the aorta can be 



