THE VESSELS. 297 



Branches : 



1. Small twigs for Art.pulmonalis and V. cava superior. 



2. Art. coronaria cordis dextra cardiaca, the coronary artery, arises from 

 the anterior surface, close above the tuber anterius bulbus aortas ; is 

 thicker, passes away behind Art. pulmonal., in the sulcus transversus, 

 on the right half of the heart towards the right and behind, and then in 

 the longitudinal groove as far as the apex of the heart. Branches : for 

 the right half of the heart, bulbus aortas and Art. pulmon. 



3. Art. coronaria cordis sinistra, arises above tuber post erius; passes off 

 into two branches. 



a. ramus anterior a. descendens on the anterior surface of the heart in 

 the longitudinal sulcus, reaching downwards as far as the apex, and 

 sending branches to the right and left ventricles. 



b. Ramus posterior s. circumflexus passes on the left to the posterior 

 surface of the heart in the sulcus transversus, and sends branches 

 to the left half of the heart. 



540. Arcus Aortce, the arch of the Aorta. 



Situation : oblique from before, backwards, and from right to 

 left (one and a half to one inch long). 



1. On the anterior and left side: the left Pleura. Nn. Phre- 

 nicus and vagus. 



2. Behind and to the right : the trachea, the commencement 

 of bronchus sinister, the oesophagus, ductus thoracicus N. recur- 

 rens, vertebral column and lymphatic glands. 



3. The highest point of the convexity directed upwards is 

 situated about ten to twelve lines below manubrium sterni. 



4. The concavity is placed above : ram. dext. Art. pulmonalis, 

 N. recurrens sinister, bronchus sinister, lymphatic glands. 



Branches : from the concavity only very small branches to the 

 bronchi (branch, supers.), pericardium, thymus ; from the con- 

 vexity : Art. anonyma \brachio-cephalica~\, art. carotis and sub- 

 clavia sinistra. 



1. Anonyma s. truncus anonymus [s. brachio-ceph.] , the common trunk of 

 Art. carotis and subclavia dextra, is thick and one inch (to two) long ; arises 

 the farthest upwards, to the right and before from the aortic arch ; is situated 

 behind the manubrium sterni and vv.jugulares communes, a little before, then 

 to the right of the trachea; it describes with the Carotis sinistra an acute an- 

 gle. Sometimes also the Carotis and subclavia sinistra, or even both carotides 

 and subclavios arise from a common trunk. 



2. Carotis communis sinistra, arises from the centre of arcus aorta to the 



