What do the superior oblique and inferior rectus muscles do?
The extraocular muscles are a group of six extrinsic muscles of the eye. These are the superior rectus, lateral rectus, inferior rectus, medial rectus, superior oblique and inferior oblique muscles. Located within the orbit, they surround the eyeball completely, facilitating its movement in various directions.
What do the superior oblique muscles do?
These muscles are unique in that they do not originate from the common tendinous ring, have an angular attachment to the eyeball, and they attach to the posterior aspect of the eyeball. The superior oblique functions explicitly to move the eye in the down-and-out position and intort the eye.
What are the two oblique muscles called?
The superior and inferior oblique muscles make an angle of 51 degrees with the optical axis. The depressing action of superior oblique (making the eye look down towards the mouth) is most effective when the eye is in an adducted position.
What is the primary action of the inferior oblique muscle?
The inferior oblique muscle externally rotates, elevates, and abducts the eye.
What muscle elevates the eyeball?
The superior tarsal muscle (Müller’s muscle) is comprised of smooth muscle and also contributes to the elevation of the upper eyelid.
What is the function of the inferior rectus?
The inferior rectus has a primary action of depressing the eye, causing the cornea and pupil to move inferiorly. The inferior rectus originates from the Annulus of Zinn and courses anteriorly and laterally along the orbital floor, making an angle of 23 degrees with the visual axis.
What Innervates the inferior oblique muscle?
The inferior oblique is innervated by the inferior division of the oculomotor nerve, which enters the muscle on its upper surface.
What Innervates the superior oblique?
The superior oblique muscle lies above the medial rectus, with the nasociliary nerve and the ophthalmic artery lying between them. Innervation is by the trochlear nerve, cranial nerve IV, which enters the posterior area of the muscle.
What is inferior oblique?
The inferior oblique is the only extraocular muscle to have its anatomic origin in the anterior orbit. The muscle runs from the medial corner of the orbit to the lateral aspect of the globe, its length approximately paralleling the tendon of insertion of the superior oblique muscle.
What are the six muscles that control eye movement?
The Six Muscles of the Eye
- Lateral Rectus. The lateral rectus is a muscle of the eye’s orbit.
- Medial Rectus. The medial rectus is also a muscle of the eye’s orbit.
- Inferior Rectus. The inferior rectus is also a muscle of the orbit.
- Superior Rectus.
- Superior Oblique.
- Inferior Oblique.