316 HUMAN ANATOMY. 



and sensory gray nuclei in floor of fourth ventricle; course, 

 passes outward across flocculus; exit, jugular foramen, in sepa- 

 rate sheath, in front of pneumogastric and spinal accessory, hav- 

 ing two gangliform enlargements upon it jugular and petrosal, 

 petrous, or ganglion of Andersch; distribution, to mucous mem- 

 brane of fauces, tonsil, pharynx, and middle ear, muscles of the 

 pharynx, and special sense of taste to the base and sides of the 

 tongue. Its branches are : 



Tympanic (Jacobson), Pharyngeal branches, 



Carotid branches, Tonsillar branches, 



Muscular branches. Lingual branches. 



10. PNEUMOGASTRIC (vagus, or par vagum), tenth nerve, 

 motor and sensory; superficial origin, from groove between 

 olivary and restiform bodies by a dozen filaments; deep origin, 

 from nuclei in floor of fourth ventricle; course, passes outward 

 across the flocculus; exit, jugular foramen in a common sheath 

 with the spinal accessory nerves; distribution (not definitely 

 known), motor nerve to the organs of respiration and voice, and 

 a motor and sensory nerve to heart, oesophagus, pharynx, and 

 stomach. Its branches are : 



Auricular (Arnold's), Thoracic cardiac, 



Pharyngeal, Anterior pulmonary, 



Superior laryngeal, Posterior pulmonary, 



Recurrent laryngeal, QEsophageal, 



Cervical cardiac, Gastric. 



It also communicates with the left hepatic sympathetic 

 plexus. 



11. SPINAL ACCESSORY, eleventh, motor nerve; superficial 

 origin, from lateral tract of medulla and spinal cord as low as 

 sixth cervical nerve; deep origin, spinal portion from anterior 

 horn of gray matter, accessory portion from gray nucleus in 

 floor of fourth ventricle; course, the spinal portion enters the 

 skull through the foramen magnum, and joins the accessory por- 

 tion in the jugular foramen; exit, jugular foramen in sheath 

 with the pneumogastric; distribution, to sterno-cleido-mastoid 

 and trapezius muscles, communicating with the cervical plexus 

 and pharyngeal and laryngeal branches of pneumogastric. 



12* HYPOGLOSSAL, or twelfth nerve, motor nerve of tongue ; 

 superficial origin, from groove between olivary and pyramidal 

 bodies by about a dozen filaments ; deep origin, from gray nucleus 

 at lowest part of floor of fourth ventricle; exit, anterior condy- 

 loid foramen; distrifaition, to the omo-hyoid (both bellies), 

 sterno-hyoid, sterno-thyroid, thyro-hyoid, and muscles of the 



