Superior rectus muscle
The superior rectus muscle is primarily responsible for the elevation of the eyeball, and it is found below the levator palpebrae superioris muscle. It passes between the tendon of the superior oblique muscle and the levator palpebrae superioris. In fact, the superior rectus muscle is loosely attached to the levator palpebrae superioris. It is also connected to the superior oblique muscle by a frenulum of the intermuscular septum.
Origin: superior aspect of the annulus of Zinn.
Insertion: vertical meridian at the superior and anterior aspects of the sclera.
Action: elevation of the eyeball; assists in adduction (the eyeball is moved inwards to the nose) and intorsion of the eyeball (medial rotation of the eyeball; top of the eyeball is rotated towards the nose).
Innervation: superior branch of the oculomotor nerve (CN III).
Blood supply: superior muscular branch of the ophthalmic artery.
Venous drainage: superior and inferior orbital veins that further drain into the cavernous sinus.