Musculus rectus dorsalis
One of four rectus muscles controlling eyeball movement. Rotates the eye dorsally (upward gaze).
Origin: Orbital periosteum around the optic foramen (common tendinous ring/annulus of Zinn)
Insertion: Dorsal sclera of the eyeball anterior to the equator
Action: Rotates the eyeball dorsally (looks up)
Innervation: Oculomotor nerve (CN III)
Damage to CN III causes the eye to deviate ventrally and laterally since the dorsal and medial rectus muscles are paralyzed, leaving the lateral rectus and ventral oblique unopposed.
Damage to CN III causes the eye to deviate ventrally and laterally since the dorsal and medial rectus muscles are paralyzed, leaving the lateral rectus and ventral oblique unopposed. Signs include: Eye deviated downward and outward; dilated pupil (mydriasis); drooping upper eyelid (ptosis); may indicate EPM, head trauma, or brain abscess.
See the Dorsal Rectus (Superior Rectus) on our interactive 3D horse model. Open 3D Model