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). (Synonym. Obliquus 

 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 

 eyeball. 



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. Flat, thin. 



Relations. Internally, with the obliquus superior; superiorly, 

 with the bony wall of the orbit. 



Action. To pull the eyeball upward. 



Rectus Inferior (Fig. 26, No. -6,3). (Synonym. Rectus ventralis.) 



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 Externus (Fig. 26, No. B, 4). (Synonym. Rectus 

 lateralis.) 



Location. External to the eyeball. 



