MUSCLES OF THE XOSE. 26[> 



12, depressor labii inferioris ; d, points to the cut ends of the levatoi-es menti ; 13, placed 

 on the left masseter, points to the buccinator ; 13', buccinator, of the right side, a 

 jjortion of the parotid duct passing through the muscle ; 14, levator anguli oris, seen 

 also on the left side behind the zygomaticus minor. The remaining references will be 

 given under the muscles of the neck. 



inserted under cover of the orbicularis muscle into the anterior surface 

 of the tarsal cartilajje. It will be described along with the muscles of 

 the orbit, 



Yarht'u's. — The muscles of this group are not subject to gfi-eat variation. 

 The external fibres of the orbicularis i^alpebramm sometimes extend farther than 

 usual, and take moi'e intimate attachment to the cornigator supercilii, or blend 

 ^yitll the zygomaticus minor or levator labii superioris. The tensor tarsi is not 

 un frequently divided into two parts. 



Actions. — The orbicularis palpebraram closes the eyelids. In the ordinary 

 closiu'c of the eye, it is chiefly the uj^per lid which moves, being depressed by the 

 superior half of the palpebral part of the muscle ; but in forcible closure both eye- 

 lids move, and not only come together, but are drawn towards the nose, at the 

 same time that the eyebrows are drawn downwards and inwards, and the neigh- 

 bouring skin of the face thrown into wrinkles, the whole fibres of the orbicularis 

 being thus contracted and drawn towards the tendo palpebraram. In these 

 circumstances the fibres which foiin the tensor tarsi, being contracted like the 

 others, compress the lachrjmial sac , and prevent the introduction into it of the lachry- 

 mal secretion from the conjunctiva. The corrugator muscles draw the skin of the 

 forehead downwards and inwards, producing longitudinal fuiTOWs. as in frowning. 

 The upper eyelid is supported l^y the levator palpebral, and droops when that 

 muscle is paralysed. On the other hand, paralysis of the orbicularis is attended, 

 by an inability to close the ej'elids. 



MUSCLES OF THE NOSE. 



Under this head may be convenient!}^ grouped not only the com- 

 pressor naris and smaller muscles which act upon the nose alone, but 

 also the pyramidalis nasi which acts on the forehead, and the common, 

 levator of the nose and lip. 



The P3rramidalis nasi, continuous with the innermost fibres of the 

 frontalis muscle, extends downwards from the root of the nose, over the 

 upper part of it, and terminates by a tendinous expansion in- connection. 

 Avith the compressor naris muscle. The muscles of opposite sides, 

 united superiorly, diverge slightly as they descend. 



The compressor naris, a thin triangular muscle, arises narrow and 

 fleshy from the canine fossa in the superior maxillary bone, and pro- 

 ceeding inwards, gradually expands into a thin aponeurosis, which is 

 partly blended with that of the corresponding muscle of the opposite 

 side, and with the pyramidalis nasi, and is partly attached to the 

 cartilage of the n(jse. It is concealed at its origin by the proper 

 elevator of the lip, and is crossed by the common elevator. 



The levator labii superioris alaeqiie nasi, the connnon elevator of 

 the lip and nose, lies alon^ the side of the nose, extending from the 

 inner margin of the orl)it to the upper lip. It arises by a pointed 

 process from the upper extremity of the nasal process of the superior 

 maxillary bone, and, as it descends, separates into two fasciculi ; one of 

 these, much smaller tlian the other, becomes attached to the wing of 

 the nose, whilst the other is prolonged to the upper lip, where it is 

 blended with the orbicularis and the special elevator muscle. It is 



