THORACIC CAVITY 87 



ventricular vein ; (4) the middle cardiac vein ; (5) the oblique 

 vein; (6) the small cardiac vein; (7) the anterior cardiac 

 veins ; and (8) the venae cordis minimae. 



The coronary sinus lies at the base of the heart, in the 

 posterior part of the coronary sulcus, between the inferior 

 border of the left atrium and the posterior border of the 

 left ventricle. It can be displayed when the apex of the 

 heart is turned upwards and to the right. Its right extremity 

 opens into the right atrium, immediately to the left of the 

 orifice of the inferior vena cava (Figs. 41, 44). At its left 



Oblique vein ~j 



^^^^^^^" G reat cardiac vein 

 Coronary sinus-^ 



Small cardiac vei 



nferior ventricular vein 

 Left marginal vein 



Middle cardiac 



Great cardiac 

 vein 



FIG. 40. The Coronary System of Veins on the Surface of the 

 Heart. (Diagram. ) 



extremity it receives the great cardiac vein. The great cardiac 

 vein ascends along the anterior longitudinal sulcus (Fig. 39), 

 where it lies in relation with the interventricular branch of the 

 left coronary artery. At the upper end of the interventricular 

 sulcus it turns round the left border of the heart, with the 

 circumflex branch of the left coronary artery, and it ends in 

 the left extremity of the coronary sinus. The inferior 

 ventricular vein or veins, from the diaphragmatic surface of 

 the left ventricle, and the middle cardiac vein, which runs 

 backwards in the inferior longitudinal sulcus, end in the 



