THE CRANIAL OR ENCEPHALIC NERVES. 



887 



1. Those formings the bronchial plexus. 



2. Those constituting^ the (Bsophmjeal nerves. 

 Collateral Branchks of the Pneumooabtric 



Nerve. — 1. Filaments of the Inferior Cervical 

 Ganglion. — Always very slender, these sometimes 

 come from tlie 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 we have named 

 the (Bsophafieal iranrh 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. 



?}. 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 w'ith a \ery 

 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 arytasnoid cartilages and that 

 of the oesophagus ; while others descend on the tliyro- 

 arytfenoid and lateral crico-arytaenoid muscles, to unite 

 with the branches coming from the recurrent, and 

 form an anastomosis analogous to the anastomosis of 

 Galim (Fig. 458, 5). 



Before penetrating the larynx — and even very near 

 its commencement — it furnishes a motor filament to 



Fig. 457, 



^^ 



ORIGIN AND DISTRIBUTION 

 OF THE EIGHTH PAIR OF 

 NERVES IN MAN. 



1, 3, 4, Medulla oblongata; 

 1, corpus pyramidale of 

 one side ; 2, pons Varolii ; 

 3, corpus olivare; 4, corpus 

 restiforrae ; 5, facial nerve; 

 6, origin of glosso-pharyn- 

 geal nerve ; 7, ganglion of 

 Andersch ; 8, trunk of the 

 nerve ; 9, spinal accessory ; 

 to, ganglion of pneumo- 

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

 pharyngeal pleius, 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, antenor 

 pulmonary branohe'? ; 19, posterior pulmonary branches; 20. oesophaareal plexus; 21, gastric 

 branches ;" 22. origin nf the spiml accessory nprve ; 23, its branches distributed to the sterno- 

 maxillaris and mastoido-huineralis ; 24, its brancheii to the trapezius muscle. 



