THE MUSCLES OF THE SCALP. 



449 



The galea aponeurotica (O.T. epicranial aponeurosis), extending between the 

 two anterior and the two posterior fleshy bellies, is a continuous membrane which 

 glides over the calvaria, and has attachments laterally to the temporal ridge, and 

 behind, between the posterior bellies, to the superior nuchal lines of the occipital 

 bone. It has no osseous attachment anteriorly. 



Nerve-Supply. The occipitalis is supplied by the posterior auricular branch of the facial 

 nerve. The frontalis is supplied by the temporal branches of the same nerve. 



Actions. The epicraneus is usually rudimentary. By the contraction of the fibres of the 

 frontalis muscle the skin of the forehead is thrown into horizontal parallel folds. 





l*v 



FRONTALIS 



_.ORBICULARIS OCULI 

 M. PROCERUS 



l" h w 



s 



J or 



CAPUT ANGULARE 

 M. NASALIS 



CAPUT ANGULARE j 



! * 



CAPUT INFRAORBITALE 

 CAPUT ZYGOMATICUM 

 CANINUS 

 ZYGOMATICUS 

 ORBICULARIS ORIS 

 BUCCINATOR 



B RISORIUS 



M. TRIANGULARIS 

 -- ]\f. QOADRATUS LABII INFERIORI3I 



MASSETER ^^mppp- 



PLATYSMA 



FIG. 398. THE MUSCLES OF THE FACE AND SCALP (Muscles of Expression). 



The extrinsic muscles of the ear are three in number : posterior, superior, and 

 anterior. They are rudimentary and usually functionless. 



The m. auricularis posterior (O.T. retrahens aurem) is a narrow fleshy slip 

 which arises from the surface of the mastoid process and is inserted into the cranial 

 surface of the auricle. It bridges across the groove between the mastoid process 

 and the auricle, and conceals the posterior auricular vessels and nerve. 



The m. auricularis superior (O.T. attollens aurem) 'is a small fan-shaped 

 muscle which arises from the temporal fascia, and descends to be inserted into 

 the top of the root of the auricle. 



The m. auricularis anterior (O.T. attrahens aurem) is a similar small muscle, 

 placed in front of the auricularis superior, and stretching obliquely between the 

 temporal fascia and the top of the root of the auricle. 



*i 



30 



