II76 



A MANUAL OF ANATOMY 



muscles of the face, including the buccinator, but not the masseter, nor the 

 levator palpebr^ superioris ; and (5) the platysma myoides. All these muscles, 

 except the posterior belly of the digastric and the stylo-hyoid, are spoken of 

 as muscles of expression. The nerve establishes free communications with 

 all three divisions of the fifth nerve, which are sensory. It also communicates 

 with the small occipital, great auricular, and superficial cervical, which are 

 branches of the cervical plexus. 



Sensory Nerves of the Face. — ^These, as stated, are twelve in 

 number on either side. With one exception they are derived from 

 the fifth cranial (trigeminal or trifacial) nerve, the exception being 

 in the case of the great auricular, which is a branch of the cervical 

 plexus. Most of them reach their distribution as independent 

 nerves, but some sensory fibres reach the skin of the face through 

 their connection with the branches of the facial nerve, as, for 

 example, in the case of the auriculo-temporal and great auricular 

 nerves. The sensory nerves are as follows : 



A. Branches of the Fifth Cranial Nerve. 



Distal Sources. 



I. Ophthalmic nerve. 



2. Superior maxillary nerve. 



3. Inferior maxillary nerve. 



Proximate Sources. 



(a) Frontal division. -j 

 (fe) Lachrymal division, 



(c) Nasal division. 



(a) Superior maxillary. 



/Orbital, or 

 ^ ' (^Temporo-malar. 



(a) Anterior division. 



(b) Posterior division. 

 {c) Inferior dental of 



posterior division. 



Nerves. 



Supra-orbital. 

 Supratrochlear. 

 Superior palpebral. 

 Infratrochlear. 

 External terminal 

 branch of nasal. 

 Infra-orbital. 

 Temporal. 

 Malar. 



Long buccal. ' 

 Auriculo-temporal. 



Mental. 



B. Facial Branches of the Great Auricular Nerve. 



Branches of the Fifth Cranial Nerve. — The supra-orbital and 

 supratrochlear nerves 'have been already described (see Index). 

 The former is distributed to the skin of the frontal region and 

 the upper part of the scalp ; and the latter to the skin of the 

 lower and central portion of the frontal region. Both these nerves 

 furnish twigs to the skin of the upper eyelid. 



The superior palpebral branch of the lachrymal nerve pierces the 

 superior palpebral ligament, and is distributed to the skin and 

 conjunctiva of the outer part of the upper eyelid, as well as to the 

 skin in the immediate vicinity of the external angular process of 

 the frontal bone. 



The infratrochlear branch of the nasal nerve emerges from the 

 orbit below the pulley of the superior oblique muscle, and furnishes 

 twigs to the skin and conjunctiva of the inner parts of the eyelids, 



