558 



THE NERVOUS SYSTEM. 



from the margin of the cornea. Nerve-supply is from the ab- 

 ducens. 



Superior Oblique. Its origin is from above the inner margin 

 of the optic foramen ; thence it passes to the inner angle of the 

 orbit, where it terminates in a rounded tendon which plays through 

 a fibrocartilaginous ring. It passes under the superior rectus, and 



FIG. 334. Ocular muscles of right side, viewed from above, after removal of roof 

 of orbit: A, frontal bone ; B, section of great wing of sphenoid ; C, section of malar 

 bone ; D, anterior clinoid process ; E, optic nerve ; 1, superior rectus ; 2, superior 

 oblique muscle with its pulley (2') and its insertion into the eyeball (2") ; 3, inter- 

 nal rectus ; 4, external rectus ; 5, common origin (ligament of Zinn) of muscles ; 

 6, cut tendon of levator palpebrse; 7, 7', 7", palpebral expansion of same; 8, inser- 

 tion of inferior oblique ; 9, intra-orbital cushion of fat ; 10, orbicularis palpebrarum 

 (Testut). 



its insertion is into the sclerotic, between the superior rectus and 

 the external rectus, midway between the cornea and the optic 

 nerve. Nerve-supply is from the trochlearis. 



Inferior Oblique. Its origin is from the orbital plate of the 

 superior maxilla, external to the lacrimal groove for the nasal 

 duct ; its insertion is into the sclerotic, between the superior rectus 



