BLOOD-VESSELS OF THE NECK. 503 



Each common carotid terminates opposite the upper bor- 

 der of the thyroid cartilage, by dividing into the external 

 and internal carotids. 



From this point, the external carotid ascends to the neck 

 of the lower jaw, where it ends in the temporal and inter- 

 nal maxillary arteries. In this course it is crossed, near its 

 origin, by the lingual nerve, then by the stylo-hyoid and 

 digastric muscles ; and, still higher, it is imbedded in the 

 parotid gland, and crossed by the facial nerve. The pla- 

 tysma, superficial fascia, and skin form the superficial 

 covering in front, while behind, it is separated from the 

 internal carotid, by the stylo-glossus and stylo-pharyngeus 

 muscles, and the glosso-pharyngeal nerve. 



The external carotid gives off ten branches, which have 

 been already detailed in describing those of the head. We 

 shall, therefore, only recapitulate here those belonging to 

 the neck. 



The superior thyroid, arising from the anterior part of 

 the external carotid, near its origin, descends beneath the 

 omo-hyoid and sterno-thyroid muscles, to the thyroid 

 gland. In its course it gives off the following branches : 



Superficial branches to the integuments and superficial 

 muscles ; hyoid, to the lower border of the hyoid bone and 

 its muscles ; superior laryngeal, which goes along with the 

 superior laryngeal nerve, through the thyro-hyoid mem- 

 brane, and is distributed to the mucous membrane and 

 muscles of the larynx ; inferior laryngeal, supplying the 



ticus. c Common carotid artery, d d Subclavian. e Brachial plexus. / g 

 Internal jugular vein, h Inferior constrictor, i (Esophagus, j Trapezius. 

 k Deltoid. / Pectoralis major its clavicular portion, m Its sternal portion. 

 n Subclavius muscle, o Axillary artery. 27 Facial artery. 28 Its submen- 

 tal branch. 29 Hypoglossal nerve. 30 Lingual artery. 31 External carotid. 

 32 Posterior auricular artery. 33 Facial nerve. 34 Glosso-pharyngeal nerve. 

 35 Occipital artery. 36 Superior laryngeal nerve. 37 Descendens noni 

 nerve. 38 Spinal accessory nerve. 39 Princeps cervicis artery. 40 supra- 

 scapular artery. 41 Transversalis colli. 42 Thyroid axis. 43 Inferior thyroid 

 artery. 44 Vertebral artery. 45 Par vagum nerve. 46 Internal mammary 

 artery. 47 Phrenic nerve. 48 Communicating nerve. 49 Second, third, and 

 fourth cervical nerves. 50 Cervical plexus. 51 Cervicalis ascendens artery. 

 52 Brachial plexus. 



