THE CRANIAL OR ENCEPHALIC NERVES. 



887 



1. Those forming the bronchial plexus. 



2. Those constituting the esophageal nerves. 



COLLATEEAL BRANCHES OF THE PnEUMOGASTRIC 



Nerve. — 1. Filaments of the Inferior Cervical 

 Ganglion. — Always very slender, these sometimes 

 come from the pharyngeal ramuscule. 



2. Pharyngeal Nerve (Fig. 459, 15). — Originat- 

 ing from the pneumogastric nerve at the middle part 

 of the superior cervical ganglion, the pharyngeal passes 

 forwards and downwards on the side of the guttural 

 pouch, and gains the upper face of the pharynx, where 

 it terminates in forming a plexus with the pharyngeal 

 branch of the ninth pair. This is a sensory-branch. 

 It gives off a large division that passes backwards to 

 the surface of the middle and posterior constrictor 

 muscles, to which it gives branches, and, throwing off 

 a filament to the external laryngeal nerve, reaches the 

 commencement of the oesophagus ; it descends on the 

 outside of that tube, by becoming distributed in its 

 muscular tunic. This division — which w^e have named 

 the cesopjhageal branch of the pharyngeal nerve — may be 

 traced on the oesophagus to the lower part of the neck, 

 and in some subjects even into the thoracic cavity. 



3. Superior Laryngeal Nerve (Fig. 458, 1). — 

 More voluminous than the preceding, and arising a 

 little lower, this nerve follows an analogous course to 

 reach the side of the larynx, where it enters the aperture 

 below the appendix of the superior border of the thyroid 

 cartilage, to be almost, entirely expended in the laryngeal 

 mucous membrane, which it endows with a very 

 exquisite degree of sensibility. 



At the inner face of the thyroid cartilage, it has 

 several branches that are directed forward, upward, 

 and backward. The first pass to the mucous membrane 

 at the base of the tongue and the two surfaces of the 

 epiglottis. The second are distributed in the lateral 

 walls of the pharynx. Of the third, some go to the 

 mucous membrane of the arytenoid cartilages and that 

 of the oesophagus ; while others descend on the thyro- 

 arytfenoid and lateral crico-arytgenoid muscles, to unite 

 with the branches coming from the recurrent, and 

 form an anastomosis analogous to the anastomosis of 

 Galien (Fig. 458, 5). 



Before, penetrating the larynx — and even very near 

 its commencement — it furnishes a motor filament to 



ORIGIN AND DISTRIBUTION 

 OF THE EIGHTH PAIR OP 

 NERVES IN MAN. 



1, 3, 4, Medulla oblongata; 

 1, corpus pyramidale of 

 one side ; 2, pons Varolii ; 

 3, corpus olivare; 4, corpus 

 restifbrme ; 5, facial nerve ; 

 6, origin of gloss^^-pharyn- 

 geal nerve ; 7, ganglion of 

 Andersch ; 8, trunk of the 

 nerve ; 9, spinal accessory ; 

 10, ganglion of pneumo- 

 gastric; 11, its plexiform ganglion; 12, its trunk; 13, its pharyngeal branch, forming the 

 pharyngeal plexus, 14, assisted by a branch from the glosso-pharyngeal, 8, and one from the 

 superior laryngeal, 15; 16, cardiac branches; 17, recurrent laryngeal branch; 18, anterior 

 pulmonarv iiranches ; 19, posterior pulmonary branches; 20, oesophageal plexus; 21, gastric 

 branches ;' 22. origin of the spinal accessory nerve; 23, its branches distributed to the sterno- 

 maxillaris and mastoido-humeralis ; 24, its branches to the trapezius muscle. 



