External Carotid Artery 27 



The veins must be gently drawn upwards or downwards, but if any 

 of them be absolutely in the way they must be tied in two places 

 and cut. The artery is then denuded, and the needle is passed from 

 without inwards, so that there may be no risk of wounding the sheath 

 of the internal carotid and jugular vein. 



If it be only the lowest part of the artery which is exposed, the 

 surgeon must be careful not to tie the internal in mistake, for the two 

 vessels lie side by side. If he can see them both, he remembers that 



Facial art. 



Mylo-hyoid n. 



Subment.art. 



Com. car. art. 



Digastric region. (HOLDEN.) 



the external is anterior and becomes superficial to the internal; 

 one of them gives off branches ; it is, of course, the external. If the 

 hypoglossal nerve be seen touching one of the trunks it must be the 

 external carotid, for, at the level at which the nerve crosses, the internal 

 is too deeply placed for the nerve to touch it. Lastly, the surgeon 

 should see that compression of the artery, which he takes to be the 

 external carotid, arrests the temporal pulse. 



If he seek the artery above the crossing of the digastric, he must 



