THE ANTERIOR PART OF THE NECK 149 



right side, the recurrent nerve crosses posterior to it, immedi- 

 ately above its origin ; and on the left side, the thoracic duct 

 turns laterally behind it, between it and the vertebral artery. 

 To its medial side, below, lie the trachea and oesophagus, 

 with the recurrent nerve in the angle between their adjacent 

 borders ; and to the medial side of its upper part are the 

 larynx and pharynx. The lobe of the thyreoid gland 

 lies either medial to the artery, separating it from the 

 oesophagus, pharynx, trachea, and larynx, or it forms a direct 

 anterior relation (Figs. 48, 53). Between its upper extremity 

 and the inferior constrictor muscle of the pharynx lies the 

 glomus caroticum. 



M. sternohyoideus 



artery 



Anterior jugular vein 

 Superior thyreoid 

 Pharynx 

 Descendens 

 hypoglossi 

 Common carotid 



Internal jugular 



Vagus 

 Sympathetic 



cricothyreoideus 

 Superior thyreoid artery 

 M. sternothyreoideus 

 Descendens hypoglossi 

 Omo-hyoid 



Common carotid 

 Vagus 



Internal jugular 

 Sympathetic 

 trunk 

 * Cervical nerve 



M. longus colli Retro-pharyngeal space Vertebral artery 



FIG. 54. Transverse section through the Neck at the level of the 

 Cricoid Cartilage. 



As a rule, the terminal divisions are the only branches of 

 the common carotid, but occasionally the superior thyreoid 

 or the ascending pharyngeal artery arises from it, instead 

 of from the external carotid. That is more especially the 

 case when the division of the common carotid takes place at 

 a higher level than usual. 



Glomus Caroticum. The glomus caroticum is a little, oval, reddish- 

 brown body, placed upon the deep aspect of the common carotid artery at 

 the point where it bifurcates. To expose it, therefore, the vessel must be 

 twisted round in such a manner that its posterior surface is turned forwards. 

 It is closely connected with the sympathetic filaments which twine around 

 the carotid vessels ; and in structure it is similar in its nature to the 

 glomus coccygeum, which rests upon the anterior aspect of the coccyx. 

 It is included, therefore, in the group of ductless glands. Entering it are 

 numerous minute arterial twigs, which take origin from the termination of 

 the common carotid and the commencement of the external carotid. The 

 in 10ft 



