a THE MUSCLES OF THE HEAD. 3t5 
face over the side of the neck, between the superficial and deep fasciz. It arises 
from the deep fascia of the pectoral region and the clavicle. It is directed 
upwards and forwards, and is partly inserted (by its middle fibres) into the lower 
border of the mandible, becoming connected with the depressor labii inferioris and 
depressor anguli oris muscles. The more anterior fibres pass across the middle 
line of the neck and decussate below the chin with those of the opposite side. The 
posterior fibres sweep over the angle of the jaw and become continuous with the 
Epicranial aponeurosis ATTRAHENS AUREM 
FRONTALIS 
ATTOLLENS 
AUREM 
OccIPITALIS ORBICULARIS PALPEBRARUM 
RETRAHENS PYRAMIDALIS NASI 
COMPRESSOR NARIS 
= — LEVATOR LABIL SUPERIORIS ALEQUE NASI 
TRAPEZIUS 
q LEVATOR LABII SUPERIORIS 
“\ZYGOMATICUS MINOR 
Parotid DEPRESSOR AL NASI 
gland ZYGOMATICUS MAJOR 
STERNO- Stenson’s duct 
MASTOID 
ORBICULARIS ORIS 
S 
SS -~Risorius 
Wi) CSS 
WW" 
{ Nein) “DEPRESSOR ANGULI ORIS 
"~DEPRESSOR LABII INFERIORIS 
O\Miasseran 
TS pilieveu MYOIDES 
Via. 275.—Tae Muscies OF THE FacE AND SCALP (muscles of expression). 
risorius muscle. The platysma myoides is the rudiment of the cervical portion of 
the panniculus carnosus of lower animals, in which it has a much more intimate 
connexion with the muscles of the face than is usually the case in man. 
THE MUSCLES OF THE SCALP. 
The muscles of the scalp comprise the muscles of the external ear and the 
occipito-frontalis muscle. 
The occipito-frontalis is a muscle with two bellies and an intervening tendon 
(the epicranial aponeurosis) which stretches uninterruptedly across the middle line of 
the cranium. The posterior belly (occipitalis) arises from the outer two-thirds of 
the superior curved line of the occipital bone as a broad flat band. The anterior 
belly (frontalis) has no bony attachments; arising from the epicranial aponeurosis 
about the level of the coronal suture, it passes downwards to the supra-orbital arch, 
where it is inserted into the orbicularis palpebrarum and corrugator supercilii 
muscles. It extends the full width of the forehead, and blends internally with the 
muscle of the opposite side. 
The epicranial aponeurosis extending between the two fleshy bellies, is a con- 
tinuous membrane which glides over the calvarium, and has attachments laterally 
to the temporal ridge, and behind between the posterior bellies to the superior 
curved line of the occipital bone. It has no osseous attachment anteriorly. The 
occipito-frontalis is usually rudimentary. By the contraction of the fibres of the 
