THE SEVENTH OR FACIAL NERVE 685 



5. Anastomotic filaments unite with the auricular Ijranch of the vagus near 

 the stylomastoid foramen. 



6. The posterior auricular nerve (N. auricularis posterior) arises from the 

 facial at its emergence from the facial canal (Fig. 514). It runs upward and back- 

 ward with the posterior auricular artery under cover of the parotid gland and sup- 

 plies the posterior auricular muscles and the skin of the conv(^x surface of the 

 external ear. It anastomoses with branches of the first and second cervical 

 nerves. 



7. The internal auricular nerve (N. auricularis internus) springs from the 

 facial close to or in common with the preceding (Fig. 514). It ascends in the paro- 

 tid gland just behind the styloid process of the conchal cartilage, passes through 

 an opening in the cartilage, and ramifies in the skin of the concave surface 

 of the ear. 



8. The digastric branch (R. digastricus) (Fig. 514) arises from the facial below 

 the auricular nerves. Its l^ranches innervate the posterior belly of the digastricus, 

 the stylo-hyoideus, and the occipito-hyoideus. At its origin it gives ofT a small 

 branch which forms a loo]5 around the great auricular artery or its posterior branch 

 and rejoins the trunk. 



9. The auriculo-palpebral nerve (N. auriculo-palpebralis) (Fig. 514) arises 

 from the upper edge of the facial near the posterior border of the ramus. It ascends 

 in the parotid gland behind the superficial temporal artery, and t('rniinat(^s in 

 anterior auricular and temporal branches. The anterior auricular branches form 

 with branches of the trigeminus the anterior auricular plexus. They innervate 

 the anterior auricular and parotido-auricularis muscles. The temporal branch 

 runs forward and inward over the temporal muscle to the inner canthus of 

 the eye, forms a plexus with the terminal branches of the ophthalmic nerve, 

 and is distributed to the orbicularis oculi, corrugator supercilii, and levator naso- 

 labiahs. 



10. The cervical branch (R. colli) (Fig. 435) arises from the ventral border 

 of the facial opjiosite to the i^receding nerve. It emerges ol)liquely through the 

 parotid gland, passes downward and backward on or near the jugular vein, and 

 anastomoses with the cutaneous branches of the cervical nerves. It gives branches 

 to the parotido-auricularis and the cervical panniculus. In its course along the 

 neck the nerve is reinforced by twngs from the cutaneous branches of the second to 

 the sixth cervical nerves. 



11. Small In-anches are detached to the guttural pouch and the parotid gland. 

 The latter (Rami parotidei) concur with branches of the superficial temporal nerve 

 in forming the parotid plexus. 



The facial nerve usually terminates after a short course on the surface of the 

 masseter by dividing into two buccal branches (Figs. 435, 461). 



1. The superior buccal nerve (X. louccalis dorsalis) passes forward on the 

 upper part of the mass(>ter, dips under the zygomaticus, and continues along the 

 lower border of the dilatator naris lateralis. It then runs under the last-named 

 muscle and anastomoses with branches of the infraorbital nerve, and is distriljuted 

 to the muscles of the check, upper lip, and nostril. 



2. The inferior buccal nerve (X. buccalis ventralis) crosses the masseter 

 ol)liciuely and continues forward along the depressor labii inferioris. It is connected 

 by variable anastomotic branches with the superior nerve. It gives collateral 

 branches to the panniculus, buccinator, and depressor labii inferioris. and ramifies 

 with the terminal branches of the inferior alveolar nerve in the lower li]). 



The buccal nerves are subject to much variation in regard to their cours(\ anastomoses, 

 and relations to the sensory compon(>nts derived from the superficial temporal nerve. Their 

 distribution is constant. The point at which the branch of the superficial temporal nerve joins 

 the facial is variable. 



