THE ANTERIOR PART OF THE NECK 247 



from it, instead of from the external carotid. This is more 

 especially the case when the division of the common carotid 

 takes place at a higher level than usual. 



Carotid Body. This 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 comes to look 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 minute 

 coccygeal body, 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 

 function of this remarkable little body is quite unknown. Most likely it 

 is a vestigial structure. 



Sterno-hypid Crico-thyrepid 



Superior thyreoid artery 

 ' ,Sterno-thyreoid 



/Descendens hypoglossi 

 /Omo-hyoid 



/Common carotid 



Anterior jugular vein 

 Superior thyreoid arten 



Pharynx 

 Descendens 

 hypoglossi 

 Common carotid 



Internal jugular 



Vagus 

 Sympathetic 



Vagus 



Internal jugular 

 .Sympathetic 

 trunk 

 ^Cervical nerves 



Longur> Vrolli Retro-pharyngeal space Vertebral artery 



FIG. 101. Transverse section through the Neck at the level of the 

 Cricoid Cartilage. 



Arteria Subclavia. The relations of the third part of the 

 subclavian artery were examined during the dissection of the 

 posterior triangle (p. 151). Those of the first and second parts 

 must now be studied.. On the right side a small portion of the 

 first part is already exposed between the lower ends of the 

 internal jugular vein and the common carotid artery ; the 

 remainder can be seen if the internal jugular vein is drawn 

 aside. On the left side the first part of the artery is concealed 

 by the commencement of the innominate vein, which must be 

 pushed aside. On both sides the second part of the artery 

 lies posterior to the scalenus anterior, which must be left in 

 position. 



The subclavian artery is the first portion of the great 

 arterial trunk which carries blood for the supply of the upper 

 n166 



