What is the action of the inferior oblique muscle?
What is the action of the inferior oblique muscle?
The inferior oblique muscle externally rotates, elevates, and abducts the eye.
What controls inferior oblique?
The inferior oblique is innervated by the inferior division of the oculomotor nerve, which enters the muscle on its upper surface. Table 10-3 lists the motor innervation of the extraocular muscles.
What is the action of the inferior rectus muscle?
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 is the action of the superior oblique muscle?
The superior oblique muscle’s primary action is eye intorsion, with secondary and tertiary actions being eye depression and abduction, respectively.
Where does the inferior oblique insertion?
Inferior oblique muscle
| Origin | Orbital surface of maxilla |
|---|---|
| Insertion | Inferolateral aspect of eyeball (deep to lateral rectus muscle) |
| Action | Abducts, elevates, externally rotates eyeball |
| Innervation | Oculomotor nerve (CN III) |
| Blood supply | Ophthalmic artery, infraorbital artery |
What is the action of the medial rectus?
Medial rectus muscle
| Origin | Common tendinous ring (annulus of Zin) |
|---|---|
| Insertion | Anterior half of eyeball medially (posterior to corneoscleral junction) |
| Action | Adducts eyeball |
| Innervation | Oculomotor nerve (CN III) |
| Blood supply | Ophthalmic artery |
What movement would be produced by contracting the inferior oblique?
inferior oblique produces To direct the eye upward or downward, two muscles contract synergistically as the two antagonist muscles relax.
What is the action of the lateral rectus?
Like other straight muscles, the lateral rectus is named by its position within the orbit relative to the eyeball. The primary action of the lateral rectus muscle is abduction of the eyeball. It works in synergy or opposition with other extrinsic muscles of the eye to produce coordinated movements and direct the gaze.
What is the action of the lateral rectus muscle?
The lateral rectus is a flat-shaped muscle, and it is wider in its anterior part. The lateral rectus muscle is an abductor and moves the eye laterally, and side to side along with the medial rectus, which is an adductor.
Where is the inferior muscle?
The inferior rectus muscle is a muscle in the orbit near the eye. It is one of the extraocular muscles. It originates from the annulus of Zinn, and inserts into the anteroinferior surface of the eye….Inferior rectus muscle.
| Inferior rectus | |
|---|---|
| Origin | annulus of Zinn at the orbital apex |
| Insertion | 6.8 mm inferior to the corneal limbus |
Is the inferior oblique muscle vertical or horizontal?
When the eye is adducted, the oblique muscles are the prime vertical movers. Elevation is due to the action of the inferior oblique muscle, while depression is due to the action of the superior oblique muscle. The oblique muscles are also primarily responsible for torsional movements.
What Innervates the superior oblique muscle?
The trochlear nerve
The trochlear nerve (IV) exits from the caudal portion of the midbrain and supplies the superior oblique muscle. In distinction to all other cranial nerves, the trochlear nerve exits from the dorsal surface of the brainstem and crosses the midline to innervate the superior oblique muscle on the contralateral side.
