ANTERIOR ASPECT OF HEAD AND NECK. 



then runs over both carotids, under the Digastric and Stylo- 

 hyoid, and around the occipital artery to the hyoid bone, and 

 then between the Mylo-hyoid and Hyo-glossus to end in the 

 tongue. It communicates near the skull with the superior 

 cervical ganglion, trunk ganglion of the vagus and loop be- 

 tween the first and second cervical; over the external carotid 

 with the pharyngeal plexus (lingual branch of the vagus); 

 and at the anterior border of the Hyo-glossus with the lingual 

 (inferior maxillary). [696] 



Branches : The recurrent (probably C. 1 and 2) arises near its 

 origin and supplies the dura of the posterior fossa. The de- 

 scendens hypoglossi (probably C. 1 and 2) descends in front of 

 the carotid sheath to the middle of the neck and joins the 

 descending cervical in a loop (ansa hypoglossi), which gives 

 branches to the Sterno-hyoid, Sterno- thyroid, and Omo-hyoid. 

 The nerve to the Thyro-hyoid (probably C. 1 and 2) descends 

 behind the great cornu of the hyoid. The lingual branches 

 (terminal) are distributed to the Hyo-glossus, Genio-hyo-glos- 

 sus, intrinsic muscles of the tongue, and (probably C. 1 and 2) 

 Genio-hyoid. [696] 



Sympathetic. The cervical part of the gangliated cord lies 

 on the prevertebral muscles, behind the carotids, and develops 

 three ganglia; there are no white rami communicantes between 

 it and the cervical spinal nerves. Its branches are central, to 

 other nerves; and peripheral, which form plexuses accom- 

 panying and supplying the vessels and viscera. [706] 



The superior cervical ganglion is at least three-quarters of an 

 inch long and lies near the base of the skull, between the inter- 

 nal carotid and internal jugular. It communicates with the 

 anterior primary divisions of the first four cervical nerves, 

 petrous ganglion of the glosso-pharyngeal, both ganglia of the 

 vagus, and hypo-glossal. Branches : The pharyngeal descends 

 behind the carotid sheath to the pharyngeal plexus. The su- 

 perior cervical cardiac descends behind the large vessels to the 

 thorax. The external carotid forms the external carotid plexus 



[77] 



