420 PRACTICAL ANATOMY. 



(i) A spinal part and (2) an accessory or internal part. The spinal part you 

 will trace to the trapezius and sterno-mastoid muscles. The accessory part 

 passes forward to the superior laryngeal nerve and pharyngeal plexus. 



Describe the liypoglossal or twelfth nerve. 



This is the motor nerve of the tongue. It leaves the cranium by the anterior 

 condyloid foramen. It supplies the depressor muscles of the hyoid bone in 

 association with the first three cervical nerves. It communicates with the vagus, 

 lingual, sympathetic, and upper three cervical nerves. 



