PNEUMOGASTRIC. 629 



of a reddish color, and about an inch in length ; it involves the whole of the 

 fibres of the nerve, except the portion of the nerve derived from the spinal 

 accessory, which blends with the nerve beyond the ganglion. 



Connecting branches. This ganglion is connected with the hypoglossal, the 

 superior cervical ganglion of the sympathetic, and the loop between the first 

 and second cervical nerves. 



The branches of the pneumo gastric are 



In the jugular fossa . . Auricular. 



Pharyngeal. 



l_ Cervical cardiac. 



f Thoracic cardiac. 



T ...i Anterior pulmonary. 



In the thorax . . . p oster ior pulmonary. 



[ (Esophageal. 

 In the abdomen . . . Gastric. 



The auricular branch (Arnold's) arises from the ganglion of the root, and is 

 joined soon after its origin by a filament from the glosso-pharyngeal ; it crosses 

 the jugular fossa to an opening near the root of the styloid process. Travers- 

 ing the substance of the temporal bone, it crosses the aqua3ductus Fallopii 

 about two lines above its termination at the stylo-mastoid foramen ; it here 

 gives off an ascending branch, which joins the facial, and a descending branch, 

 which anastomoses with the posterior auricular branch of the same nerve : the 

 continuation of the nerve reaches the surface between the mastoid process and 

 the external auditory meatus, and supplies the integument at the back part of 

 the pinna. 



The pharyngeal branch, the principal motor nerve of the pharynx and soft 

 palate, arises from the upper part of the inferior ganglion of the pneumogastric, 

 receiving a filament from the accessory portion of the spinal accessory ; it 

 passes across the internal carotid artery (in front or behind), to the upper border 

 of the Middle Constrictor, where it divides into numerous filaments, which 

 anastomose with those from the glosso-pharyngeal, superior laryngeal, and 

 sympathetic, to form the pharyngeal plexus, from which branches are distributed 

 to the muscles and mucous membrane of the pharynx. As this nerve crosses 

 the internal carotid, some filaments are distributed, together with those from 

 the glosso-pharyngeal, upon the wall of this vessel. 



The superior laryngeal is the nerve of sensation to the larynx. It is larger 

 than the preceding, and arises from the middle of the inferior ganglion of the 

 pneumogastric. It descends, by the side of the pharynx, behind the internal 

 carotid, where it divides into two branches, the external and internal laryngeal. 



The external laryngeal branch, the smaller, descends by the side of the 

 larynx, beneath the Sterno-thyroid, to supply the Crico-thyroid muscle and the 

 thyroid gland. It gives branches to the pharyngeal . plexus, and the Inferior 

 Constrictor, and communicates with the superior cardiac nerve, behind the 

 common carotid. 



The internal laryngeal branch descends to the opening in the thyro-hyoid 

 membrane, through which it passes with the superior laryngeal artery, and is 

 distributed to the mucous membrane of the larynx, and the Arytenoid muscle, 

 anastomosing with the recurrent laryngeal. 



The branches to the mucous membrane are distributed, some in front, to the 

 epiglottis, the base of the tongue and the epiglottidean glands; while others 

 pass backwards, in the aryteno-epiglottidean fold, to supply the mucous mem- 

 brane surrounding the superior orifice of the larynx, as well as the membrane 

 which lines the cavity of the larynx as low down as the vocal chord. 



