66 DISSECTION OF THE NECK. 
one of the intrinsic muscles of the larynx, the crico- 
thyroid. The superior laryngeal anastomoses with 
the inferior laryngeal by a large branch passing be- 
neath the wing of the thyroid cartilage. 
Ir. Somewhat posterior to the origin of the superior 
laryngeal the sympathetic trunk separates from the 
vagus. Follow it forward a short distance until it 
ends in the saperzor cervical ganglion. 
Just anterior to its ganglionic enlargement the vagus 
enters the skull. Emerging at about the same point 
the following cranial nerves can be found: 
12. The Hypoglossal, or 12th Cranial Nerve, is very 
large ; it runs forward beneath the digastric and mylo- 
hyoid muscles to enter the tongue, to which it supplies 
motor fibres. It leaves the skull through the anterior 
condylar foramen. 
a. THE DEscENDENS HyrocG.tossi, a branch of the 
hypoglossal, arises from the convex border of the 
loop made by the hypoglossal and passes posteriorly 
along the neck superficial to the vagus and carotid ; 
in its course it soon unites with a branch of the first 
cervical spinal nerve, and from the common trunk 
branches are given to the sterno-thyroid and sterno- 
hyoid muscles. The nerve is very long, reaching to 
the posterior third of the neck. 
13. The Spinal Accessory, or 11th Cranial Nerve, 
leaves the skull through the jugular foramen in com- 
pany with the vagus and glosso-pharyngeal; it runs 
posteriorly upon the sterno-mastoid muscle, within 
which it soon disappears. It supples this and other 
muscles of the neck with motor fibres. 
14. The Glosso-pharyngeal, or 9th Cranial Nerve, 
appears in the same place close to the vagus; it turns 
inward to the mid-line and disappears in the muscles 
