MUSCLES OF THE EYELIDS. 



553 



that aperture (fig. 202), to which the above name has been 

 given : they are seldom visible without a lens. The anterior slip anterior and 

 4 ) passes from the cartilage of the aperture to the integument of 

 he margin of the nostril ; and the posterior ( 5 ) arising from the 



the 



upper jawbone and the small quadrate cartilages, ends also in the 



integuments of the nostril. 



Action. The fibres enlarge the nasal opening by raising and use. 

 everting the outer edge. 



The DEPRESSOR AUE XASi (fig. 202 6 ) will be seen if the upper 

 lip is everted, and the mucous membrane is removed by the side of 

 the frsenum of the lip. It arises below the nose from the incisor 

 fossa of the superior maxilla, and ascends to be inserted into the 

 septum narium and the posterior part of the ala of the nose. 



Corrugator supercilii. 



Internal tarsal ligament. 

 Pyramidalis nasi. 



Levator labii superioris 

 alseque nasi. 



Levator labii superioris 

 Levator anguli oris. 



Depressor labii inferioris. 

 Depressor angnli oris. 



Orbicularis palpebrarum 

 (palpebral portion). 



Orbicularis palpebrarum 

 (orbital portion). 



Attolens aurem. 

 Attrahens aurem. 



Masseter (deep part). 



Zygomaticus minor 



(too large). 

 Zygomaticus major. 



Masseter (superficial 

 parts ; some cut away). 



Buccinator. 

 FIG. 203. DIAGRAM OF THE MUSCLES OP THE FACE. 



Action. By drawing down and turning in the edge of the use. 

 dilated nostril, it restores the aperture to its usual size. 



MUSCLES OF THE EYELIDS. The muscles of the eyelids and eve- Four , 



i i- i i-i-Ti muscles of 



brow are tour in number, viz., orbicularis palpebrarum, corrugator eyelids and 



supercilii, levator palpebrae superioris. and tensor tarsi * : the two brow - 

 latter are dissected in the orbit, and will be then described. 



The ORBICULARIS PALPEBRARUM (fig. 203) is the sphincter 

 muscle closing the opening between the eyelids. It is a flat and rum: 

 thin layer, which extends from the margin of the lids beyond the 

 circumference of the orbit. From a difference in the characters of 

 the fibres, a division has been made of them into two parts outer, two parts. 

 or orbital, and inner, or palpebral. 



* The tensor tarsi muscle is sometimes described as part of the orbicularis. 



