THE ORBITAL REGION 



369 



nerves which supply the integument of the eyelids. The tarsal ligaments pre- 

 viously described are reenforcing bands of this fascial septum. 



The Levator palpebrae superioris is thin, flat, and triangular in shape. It 

 arises from the under surface of the lesser wing of the sphenoid, above and in 

 front of the optic foramen, from which it is separated by the origin of the Superior 



Tendon of Obliquns superior 

 Orbital plate of frontal bone 

 Levator palpebrc? superioris 



Kuctui superior ( J~"'i 



E-jSEsU^'./^ 



Orbicularis pa Ipebraru m 

 Superior tarsal plate 

 Upper eyelid 



Optic nerve 



Rectus inferior 

 JBoof of ant.rum of Highmore 



Obliquus' inferior 



FIG. 291. Sagittal section of left orbital cavity. 



Lower eyelid 

 Inferior tarsal plate 

 Orbicularis palpebrarum 



rectus (Fig. 293). At its origin it is narrow and tendinous, but soon becomes 

 broad and fleshy, and terminates anteriorly in a wide aponeurosis, which splits 

 into three lamellne. The superficial lamella blends with the superior palpebral 

 ligament, and is prolonged forward above the superior tarsal plate to the palpebral 

 part of the Orbicularis palpebrarum and to the deep surface of the skin of the 



FIG. 292. Muscles of the right orbit. 



upper eyelid. The middle lamella, largely made up of unstriped muscle fibres 

 (superior tarsal muscle}, is inserted into the upper margin of the superior tarsal 

 plate, while the deepest lamella blends with an expansion from the sheath of 

 the Superior rectus muscle and with it is attached to the superior fornix of the 

 conjunctiva. 



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