PNEUMOGASTRIC NERVE 



531 



is united by two or three filaments with the ganglion of the glosso- 

 pharyngeal. It is a true ganglion, containing nerve-cells. After the 

 nerve has emerged from the cranial 

 cavity, it presents on its trunk an- 

 other grayish enlargement, half an 

 inch to an inch (12 to 25 millimeters) 

 in length, called the ganglion of the 

 trunk. This has a plexiform struc- 

 ture, the white fibres being mixed 

 with grayish fibres and nerve-cells. 

 The exit of the nerve from the cranial 

 cavity is by the jugular foramen, or 

 posterior foramen lacerum, in com- 

 pany with the spinal accessory, the 

 glosso-pharyngeal nerve and the in- 

 ternal jugular vein. 



Anastomoses. There are occa- 

 sional filaments of communication 

 that pass from the spinal accessory to 

 the ganglion of the root of the pneu- 

 mogastric, but these are not constant 

 After both nerves have emerged 

 from the cranial cavity, an important 

 branch of considerable size passes 

 from the spinal accessory to the 

 pneumogastric, with which it be- 

 comes closely united. Experiments 

 have shown that these filaments from 

 the spinal accessory pass in great part 

 to the larynx by the inferior laryn- 

 geal nerves. 



In the aquaeductus Fallopii, the 

 facial nerve gives off a filament of 

 communication to the pneumogastric, 

 at the ganglion of the root. This 

 filament, joined at the ganglion by 

 sensory filaments from the pneumo- 

 gastric and some filaments from the 

 glosso-pharyngeal, is called the au- 

 ricular branch of Arnold. By some 

 anatomists it is regarded as a branch of the facial and by others it is 

 described with the pneumogastric. 



Fig. 130. Anastomoses of the pneumogastric 

 (Hirschfeld). 



I, facial nerve ; 2, glosso-pharyngeal nerve ; 

 2', anastomoses of the glosso-pharyngeal with 

 the facial ; 3, 3, pneumogastric, with its two 

 ganglia ; 4, 4, spinal accessory ; 5, sublingual 

 nerve ; 6, superior cervical ganglion of the 

 sympathetic ; 7, anastomotic arcade of the first 

 two cervical nerves ; 8, carotid branch of the 

 superior cervical ganglion of the sympathetic ; 

 9, nerve of Jacobson ; 10, branches of this 

 nerve to the sympathetic; n, branch to the 

 Eustachian tube; 12, branch to the fenestra 

 ovalis ; 13, branch to the fenestra rotunda ; 

 14, external deep petrous nerve ; 15, internal 

 deep petrous nerve ; 16, otic ganglion ; 17, au- 

 ricular branch of the pneumogastric ; 18, anas- 

 tomosis of the pneumogastric with the spinal 

 accessory ; 19, anastomosis of the pneumogastric 

 with the sublingual ; 20, anastomosis of the 

 spinal accessory with the second pair of cervi- 

 cal nerves ; 21, pharyngeal plexus ; 22, supe- 

 rior laryngeal nerve; 23, external laryngeal 

 nerve; 24, middle cervical ganglion. 



