376 THE MUSCULAR SYSTEM. 
frontalis muscle the skin of the forehead is thrown into horizontal parallel 
folds. 
The extrinsic muscles of the ear are three in number: retrahens, attollens, 
and attrahens aurem. 
The retrahens aurem (m. auricularis posterior) is a narrow fleshy slip which 
arises from the surface of the mastoid process and is inserted into the deep surface 
of the pinna. It bridges across the groove between the mastoid process and the 
pinna, and conceals the posterior auricular vessels and nerve 
The attollens aurem (m. auricularis superior) 1s a small fan-shaped muscle 
which arises from the temporal fascia, and descends vertically to be inserted into 
the top of the root of the pinna. 
The attrahens aurem (im. auricularis anterior) is a similar small muscle, placed 
in front of the attollens, and stretching obliquely between the temporal fascia and 
the top of the root of the pinna. 
These two muscles conceal branches of the temporal vessels as they he on the 
temporal fascia. 
The ear muscles are rudimentary and usually functionless. 
THE MUSCLES OF THE FACE. 
The muscles of the face are divided into three groups, associated with the 
several apertures of the eye, nose, and mouth. 
1. The muscles of the eyelids include four muscles: the levator palpebre 
superioris (described with the orbital muscles), orbicularis palpebrarum, tensor tarsi, 
and corrugator supercilii. 
The orbicularis palpebrarum (im. orbicularis oculi) is a transversely oval 
sphincter muscle surrounding and occupying the eyelids. It is divisible into an 
external portion (pars orbitalis) composed of coarse fibres, spreading on to the forehead, 
temple, and cheek, and an internal portion (pars palpebralis), composed of finer 
fibres, which occupies the eyelids beneath the skin. At the inner canthus of the 
eye the muscle (by its palpebral fibres) gains an attachment to the tarsal ligament 
and the borders of the naso-lachrymal groove. The fibres which extend along the 
margins of the lids constitute a separate ciliary bundle. The fibres of the orbicularis 
palpebrarum enclose the lachrymal sac and the canaliculi. The posterior fibres, 
extending between the posterior edge of the naso-lachrymal groove and the tarsal 
ligaments behind the lachrymal sac, constitute the tensor tarsi muscle. 
Externally the orbicularis palpebrarum has no bony attachment; so that when 
it contracts and closes the eyelids, both lids at the same time tend to be drawn 
inwards towards the inner canthus of the eye. 
The corrugator supercilii arises from the nasal eminence, and passing horizon- 
tally outwards, blends with the upper fibres of the preceding muscle on its under 
surface. The contraction of this muscle throws the forehead into vertical folds. 
2. The muscles of the nose comprise five small muscles proper to the nose, and 
one common to the nose and upper lp: the pyramidalis nasi, compressor naris, 
dilatores naris (anterior and posterior), depressor ale nasi, and levator labii 
superioris aleeque nasi. They are all small and feeble. 
The pyramidalis nasi arises from the occipito-frontalis muscle and the skin 
over the glabella; it is inserted into a membrane stretching over the nose, which 
also gives attachment to the compressor naris. 
The compressor naris (m. nasalis) arises by a narrow origin from the superior 
maxilla, under cover of the levator labii superioris aleeque nasi. It passes forwards 
over the bridge of the nose, and ends in a membranous insertion common to it and 
the previous muscle, 
The dilatores naris are feeble muscular slips placed on the outer side of the 
margin of the nostril, one anteriorly, the other posteriorly. 
The depressor ale nasi is a small muscle arising from the upper part of the 
incisor fossa of the maxilla; it divides into two parts as it passes upwards and 
inwards, and is inserted into the ala and the septum of the nose (depressor septi). 
