Carotis externa. 



189 



R .no 



.ant. 



transv. 

 fad el 



The commom carotid, Ca- 



rotis communis, ascends to the upper 



margin of the thyroid cartilage with- 

 out giving off any branches, and 



there divides into the external and 



internal, Carotis externa and internet. 

 The external carotid is 



covered by the Platysma myoides, by 



the superficial layer of the cervical 



fascia and the facial vein, passes 



into the substance of the parotid 



gland and behind the condyle of 



the lower jaw, and divides into two 



terminal branches : the temporal, 



Art. temporalis superficialis, and inter- 

 nal maxillary, Art. maxillaris 



internet. From the anterior portion 



of the external carotid arise: 



a) The superior thyroid, 



Art. tliyreoidea superior, which curves 

 downwards and forwards in an arched 

 and tortuous manner to the thyroid 

 gland. It gives off the superior 



laryngeal, Art. laryngea superior, 5 31. Diagram of the Rami- 

 which pierces the thyro-hyoid mem- ficatioilS of the External 

 brane and supplies the muscles, Carotid, 



mucous membrane and glands of the 

 larynx and epiglottis ; also mus- 

 cular branches. (See Fig. 532, 533. In Fig. 533 - - the original 

 was a dried specimen the superior laryngeal artery appears as if pushed 

 out of its position ; it must be imagined as running in the Sinus pyriformis.) 

 b) The lingual artery, Art. lingualis, arises opposite the great 

 cornu of the hyoid bone, and passing between the M. hyo-glossus and 

 M. constrictor pliaryngis medius, reaches the tongue. Its branches are the 

 hyoid, Eamus hyoideus ; the Art. dorsalis linguae to the mucous mem- 

 brane of the dorsum of the tongue; the sublingual, Art. sublingualis, 

 to the floor of the mouth. The continuation of the lingual artery is 

 called r a n i n e artery, Art. ranina or Art. prof unda linguae (see 

 Fig. 541). It communicates with the artery of the other side only by 

 means of capillaries. 



25* 



