54( 



ANGIOLOGY 





what oval figure. The ascending aorta is contained within the pericardium, and 

 is enclosed in a tube of the serous pericardium, common to it and the pulmonary 

 artery. 



Relations. The ascending aorta is covered at its commencement by the trunk of the pul- 

 monary artery and the right auricula, and, higher up, is separated from the sternum by the 

 pericardium, the right pleura, the anterior margin of the right lung, some loose areolar tissue, 

 and the remains of the thymus; posteriorly, it rests upon the left atrium and right pulmonary 

 artery. On the right side, it is in relation with the superior vena cava and right atrium, the 

 former lying partly behind it; on the left side, with the pulmonary artery. 



Right vagu-\- 

 Recurrent nerve 



Left vagus 

 Left phrenic 

 Thoracic duct 



FIG. 506. Plan of the 

 branches. 



FIG. 505. The arch of the aorta, and its branches. 



Branches. The only branches of the ascending aorta are the two coronary 

 arteries which supply the heart; they arise near the commencement of the aorta 

 immediately above the attached margins of the semilunar valves. 



The Coronary Arteries. The Right Coronary Artery (a. coronaria [cordis] dextra) 

 arises from the right anterior aortic sinus. It passes at first between the conus 

 arteriosus and the right auricula and then runs in the right portion of the coronary 

 sulcus, coursing at first from the left to right and then on the diaphragmatic surface 

 of the heart from right to left as far as the posterior longitudinal sulcus, down 



