PHARYNX AND GULLET IN THE HOUSE. 25 



where these form the superior mediastinum. It passes be- 

 tween the crura of the diaphragm or midriff, and ends in the 

 stomach, at a right angle, about the centre of its upper and 

 anterior part. 



The several parts of the mouth now spoken of are freely 

 supplied with blood by arteries derived on each side from the 

 external carotid artery, which blood is returned by correspond- 

 ing veins terminating finally in the right and left jugular veins. 

 The pharynx also is supplied with blood from the external caro- 

 tid, while the gullet receives branches from the posterior aorta. 

 The external carotid artery is itself one of the three branches 

 into which, on each side, the carotid artery splits near the top 

 of the larynx, the other two being the internal carotid and the 

 anastomotic branch. The right and left carotid arteries, which 

 there split, are themselves branches of one common trunk 

 namely, the common carotid. This common carotid is a large 

 artery, though no more than an inch in length, issuing by the 

 upper part of the anterior aperture of the chest, on the fore 

 part of the windpipe, and there dividing, as just said, into the 

 right and left carotids. This short artery, the common 

 carotid, is itself the continued trunk of the right anonymous 

 artery, which, again, is one of the two branches into which the 

 anterior aorta divides namely, the right anonymous artery 

 and the left anonymous artery. Of these the right anonymous 

 artery is much the larger, inasmuch as the right affords 

 branches to the right anterior extremity as well as to the 

 head, while the left gives no branches to the head, but only 

 corresponding branches to the left anterior extremity. The 

 anterior aorta is a very short trunk, even less than an inch in 

 length, which comes off from the aorta beneath the fourth 

 dorsal vertebra ; or perhaps, more correctly, it is one of the 

 two great divisions into which the aorta, springing from the 

 left ventricle of the heart, breaks, about four inches from its 



