556 



THE VASCULAR SYSTEMS 



auriculoventricular groove (sulcus coronarius]. It contains the trunks of the 

 nutrient vessels of the heart, but is obliterated, in front, where it is crossed by the 

 root of the pulmonary artery. 



The interauricular groove, separating the two auricles, is scarcely marked on the 

 postero-inferior aspect, while superiorly it is hidden by the pulmonary artery and 

 aorta. The ventricles are separated by two furrows, the interventricular grooves 

 (sulci longitudinales), one of which (sulcus longitudinalis anterior) is situated on 

 the antero-superior surface close to the left margin of the heart, the other (sulcus 

 longitudinalis posterior) on the postero-inferior surface near the right margin; 

 these grooves extend from the base of the ventricular portion to a point a little to 

 the right of the apex of the heart. 



LEFT APPENDIX 

 AURICULA? 

 LEFT AURICULO- 

 VENTRICULAR 

 GROOVE 



CORONARY 

 SINUS 



SULCUS 

 TERMINALIS 



INTERAURICUU 

 SULCUS 



CESOPHAGUS 



FIG. 415. Base of the heart in place. 



The attachments of the pericardium are outlined in red. 

 (Poirier and Charpy.) 



The base (basis cordis) (Fig. 415), directed backward, a little upward, and to the 

 right, is separated from the fifth, sixth, seventh, and eighth thoracic vertebrae by the 

 oesophagus, aorta, and thoracic duct. It is formed mainly by the left auricle, 

 and, to a small extent, by the back part of the right auricle. Somewhat quadri- 

 lateral in form, it is in relation above with the bifurcation of the pulmonary artery, 

 and is bounded below by the posterior part of the auriculoventricular sulcus, 

 containing the coronary sinus. On the right it is limited by the sulcus terminalis 

 of the right auricle, and on the left by the vestigial fold and oblique vein of Mar- 

 shall. The four pulmonary veins, two on either side, open into the left auricle, 

 while the superior vena cava opens into the upper-and the inferior vena cava into 

 the lower part of the right auricle. 



The apex (apex cordis} is directed downward, forward, and to the left, and is 



