330 



THE MUSCULATURE 



ous tissue of the scalp. That covering the subcutaneous muscle of the neck is less firmly fused 

 wkh the sSbcutaneoSs tissue. In the facial region the more superficial niuscles are so closely 

 rmbedded in the subcutaneous tissue that no distinct fascia3 intervening between the muscles 

 Ind the skin can, as a rule, be distinguished. Of the deeper muscles of the faciahs group the 

 buccinator alone possesses a distinct fascia. This muscle lies upon the mucous membrane of the 

 latSS wall of the mouth, and is covered externally by a fascia continued into the fascia investing 



*'' Zsi^-B^rt'su^cutanL" pr^^^^^^^ Between the periosteum at the tip of the chin 



and the overlving tissue. Bursa subcutanea prominentise laryngeae. In front of the junction 

 of the right and left lamina of the thyreoid cartilage. 



Fig. 341.— The Superficial Muscles op the Head and Neck. 



Frontalis 



Orbicularis oculi 



Procerus 

 Quadr. labii sup. 

 caput annulare 

 Nasalis, pars transversa 

 Dilator naris anterior^ 

 Dilator naris posterior* 



Quadr. labii sup. 

 caput infraorbitale 



Caput zygomaticum 



Caninus 

 Orbicularis oris 



Quadratus labii inferioris 

 Triangularis 



Galea apo- 

 neurotica 



Auricularis 

 superior 



MUSCLES 



The muscles of the facialis group may be conveniently subdivided as follows:— 

 (a) Cervical: the platysma. (6) Oral: the orbicularis oris and the mcisiyus 

 labii sui)erioris and inferioris; the quadratus labii superioris and interions; the 

 caninus, zygomaticus, risorius, and triangularis; and the buccinator, [c) 

 Mental, (d) Nasal: the nasalis, depressor septi, and the dilatores naris. {e) 

 Periorbital: the ()rl)icularis oculi, corrugator, and procerus. (/) Epicranial: tne 

 frontalis and occipitalis, with the galea aponeurotica. (p) Auricuar : anterior, 

 superior, and posterior. With these the temporalis superhciahs is also described. 



(a) CERVICAL MUSCLE 



The platysma is a large, thin, quadrangular muscle which runs obliquely from 

 the chin, the corner of the mouth, and the lower part of the cheek across the 



