THE HYPOGLOSSAL 353 



(c) In the chest: The thoracic cardiac branches, the right 

 from the trunk of the vagus and from the recurrent branch, 

 the left from the latter only. They join the deep cardiac 

 plexus. 



/V///0/W/-// //rnv.v, two or three anterior, join the sympathetic 

 and form the anterior plexus on the root of the lung. The 

 posterior, larger and more numerous, join branches from the 

 second, third, and fourth thoracic ganglia to form the posterior 

 plexus. Offsets from these nerves accompany the bronchi 

 throughout the lung. 



The esophageal, above and below the preceding. The lower 

 and larger branches come from the esophageal plexus. 



(d) Gastric branches: These are the terminal branches of 

 the vagi. The right, to the posterior surface, join the celiac, 

 splenic, and left renal plexuses. The left, to the anterior 

 surface and lesser curvature, join the right nerve, the sympa- 

 thetic, and the hepatic plexus. 



The Eleventh Pair 



The eleventh, or spinal accessory, consists of a spinal portion 

 and an accessory part to the vagus. The latter part arises as 

 five or six filaments from the lateral tract of the medulla, 

 below the origin of the vagus. It sends some filaments into 

 the ganglion jugulare of the vagus, and joins that nerve below 

 the ganglion cervicale, being continued, for the most part, 

 into the pharyngeal and superior laryngeal branches. 



The spinal portion arises from the lateral column of the cord 

 as low as the sixth cervical nerve, the fibers being connected 

 with the anterior horn of gray matter. This part then ascends, 

 between the posterior nerve roots and the ligamentum den- 

 ticulatum, through the foramen magnum, then out again by 

 the jugular foramen, lying in the sheath of the vagus, and 

 here communicates with the accessory portion. After its 

 exit from the skull it crosses the internal jugular vein and 

 pierces the sternomastoid to end in the trapezius. 



The Hypoglossal 



The twelfth, or hypoglossal, nerve arises by ten to fifteen 

 filaments from the groove between the pyramidal and olivary 

 23 



