622 CRANIAL NERVES. 



cartilaginous substance which fills in that aperture, and enters the carotid canal 

 on the outer side of the carotid artery, to join the carotid plexus. 



This description of the Vidian nerve as a branch from the ganglion, is the 

 more convenient anatomically, inasmuch as the nerve is generally dissected 

 from the ganglion, as a single trunk dividing into two branches. But it is more 

 correct, physiologically, to describe the Vidian as being formed by the union 

 of the two branches (great petrosal and carotid) from the facial and the sympa- 

 thetic, and as running into the ganglion. The filaments, which are described 

 above as given off from the Vidian nerve, would then be regarded as branches 

 from the ganglion which are merely inclosed in the same sheath as the Vidian. 



The pharyngeal nerve (pterygo-palatine) is a small branch arising from the 

 back part of the ganglion, occasionally together with the Vidian nerve. It 

 passes through the pterygo-palatine canal with the pterygo-palatine artery, 

 and is distributed to the lining membrane of the pharynx, behind the Eusta- 

 chian tube. 



INFERIOR MAXILLARY NERVE. (Fig. 344.) 



The Inferior Maxillary Nerve distributes branches to the teeth and gums of 

 the lower jaw, the integument of the temple and external ear, the lower part 

 of the face and lower lip, and the muscles of mastication ; it also supplies the 

 tongue with one of its special nerves of the sense of taste. It is the largest 

 of the three divisions of the fifth, and consists of two portions, the large or 

 sensory root proceeding from the inferior angle of the Casserian ganglion ; and 

 the small or motor root, which passes beneath the ganglion, and unites with the 

 inferior maxillary nerve, just after its exit through the foramen ovale. Imme- 

 diately beneath the base of the skull this nerve divides into two trunks, 

 anterior and posterior. 



The anterior, and smaller division, which receives nearly the whole of the 

 motor root, divides into five branches, which supply the muscles of mastication. 

 They are the masseteric, deep temporal, buccal, and two pterygoid. 



The masseteric branch passes outwards, above the External Pterygoid muscle, 

 in front of the temporo-maxillary articulation, and crosses the sigmoid notch, 

 with the masseteric artery, to the Masseter muscle, in which it ramifies nearly 

 as far as its anterior border. It occasionally gives a branch to the Temporal 

 muscle, and a filament to the articulation of the jaw. 



The deep temporal branches, two in number, anterior and posterior, supply the 

 deep surface of the Temporal muscle. The posterior branch, of small size, is 

 placed at the back of the temporal fossa. It is sometimes joined with the mas- 

 seteric branch. The anterior branch is reflected upwards, at the pterygoid ridge 

 of the sphenoid, to the front of the temporal fossa. It is occasionally joined 

 with the buccal nerve. 



The buccal branch pierces the External Pterygoid, and passes downwards 

 beneath the inner surface of the coronoid process of the lower jaw, or through 

 the fibres of the Temporal muscle to reach the surface of the Buccinator, upon 

 which it divides into a superior and an inferior branch. It gives a branch to 

 the External Pterygoid during its passage through that muscle, and a few 

 ascending filaments to the Temporal muscle, one of which occasionally joins 

 with the anterior branch of the deep temporal nerve. The tipper branch sup- 

 plies the integument and upper part of the Buccinator muscle, joining with the 

 facial nerve round the facial vein. The lower branch passes forwards to the 

 angle of the mouth; it supplies the integument and Buccinator muscle, as well 

 as the mucous membrane lining the inner surface of that muscle, and joins the 

 facial nerve. 



The pteryrjoid branches are two in number, one for each Pterygoid muscle. 

 The branch to the Internal Pterygoid is long and slender, and passes inwards 

 to .enter the deep surface of the muscle. This nerve is intimately connected at 

 its origin with the otic ganglion. The branch to the External Pterygoid is 



