58 DISSECTION OF THE VASCULAR SYSTEIu. 



are given off separately though close together, and 

 pass forward in the neck, one on each side of the 

 trachea. 



Make a median mcision along the ventral stirface 

 of the neck from the larynx to the sternum. Clear 

 away the muscles lying on the trachea and the common 

 caj'otids luill be exposed. Each gives off the following 

 brandies : 



5. The Superior Thyroid Artery, given off at the 

 level of the thyroid body, to which it is chiefly dis- 

 tributed. 



6. The Internal Carotid. At the level of the larynx 

 the common carotid divides into the internal and ex- 

 ternal carotid. The former is much smaller and 

 passes to the base of the skull, which it enters through 

 the carotid foramen, being one of the arteries which 

 supplies the brain with blood. 



7. The External Carotid seems to be the direct 

 continuation of the common carotid. It gives off the 

 following branches : 



8. The Occipital Artery is a small branch arising 

 close to the internal carotid and running parallel to it. 

 It is distributed to the exterior of the skull in the 

 occipital region. 



9. The Lingual Artery, the third branch of the ex- 

 ternal carotid, is a large artery distributed chiefly to 

 the tongue. 



10. The Facial Artery is a small branch given off a 

 short distance beyond the lingual. It usually gives a 

 branch to the submaxillary gland. 



11. The Posterior Auricular, the next branch, is given 

 off from the outer side of the carotid, supplying the 

 tissues on the posterior side of the ear. A short dis- 

 tance from its origin it may give a branch to the sub- 

 maxillary gland. 



