MYOLOGY 127 



Origin. — ^From the orbital septum just back of the inner canthus, 

 the fibers passing backward and forward.- 



Insertion. — 'Into the sclera, anterior to the sclerotic plates. 



Shape. — Small, thin, fan-shaped. 



Relations. — With the eyeball, superiorly; at its extremities with 

 the superior rectus, interiorly. 



Action. — Rotates the eyeball. 



Obliquus Inferior (Fig. 26, No. B, 6). (Synonjon. — ObUquus 

 ventralis.) 



Location. — Inferior to the eyeball. 



Origin. — From the interorbital septum near the inner canthus 

 of the eye. 



Insertion. — By a broad expansion to the inferior portion of the 

 eyebaU. 



Shape. — Tendinous at its insertions; fan-shaped as it passes down- 

 ward and outward. 



Relations. — Internally, with the eyeball; and externally, with the 

 bony orbital wall, with the inferior rectus muscle, inferiorly. 



Action. — Aids in rotating the eye; opposes the obliquus superior. 



Rectus Superior (Fig. 26, No. B, i). (Synonym. — Rectus dorsalis.) 



Location. — Superior to the eyeball. 



Origin. — Along the supero-posterior border of the optic foramen. 



Insertion. — To the sclera just within the margin of the bony circle 

 of the eye. 



Shape.— F\a,t, thin. 



Relations. — Internally, with the obliquus superior; superiorly, 

 with the bony wall of the orbit. 



Action.— To puU the eyeball upward. 



Rectus Inferior (Fig. 26, No. B, 3). (Synonym. — Rectus ventraUs.) 



Location. — Inferior to the eyeball. 



Origin. — From the inferior border of the optic foramen. 



Insertion. — To the lower portion of the eyeball within the margin 

 of the bony circle of the eye. 



Shape. — Thin, fan-shaped. 



Relations. — Superiorly, with the eyeball; inferiorly, with the 

 bony wall of the orbit. 



Action. — Pulls the eyeball downward. 



Rectus Extemus (Fig. 26, No. B, 4). (Synonym. — Rectus 

 lateralis.) 



Location. — External to the eyeball. 



