Extraocular Muscles - Mnemonic Devices

Mnemonic Devices

A good mnemonic to remember which muscles are innervated by what nerve is to paraphrase it as a molecular equation: LR₆SO₄R₃.

• Lateral Rectus - Cranial Nerve VI
• Superior Oblique - Cranial Nerve IV
• the Rest of the muscles - Cranial Nerve III.

Another way to remember which nerves innervate which muscles is to understand the meaning behind all of the Latin words.

• The fourth cranial nerve, the trochlear, is so named because the muscle it innervates, the superior oblique, runs through a little fascial pulley that changes its direction of pull (the trochlea of superior oblique). This pulley exists in the superiomedial corner of each orbit, and "trochl-" is Latin for "pulley."
• The sixth cranial nerve, the abducens, is so named because it controls the lateral rectus, which abducts the eye (rotates it laterally) upon contraction.
• The third cranial nerve, the oculomotor, is so named because it is in charge of the movement (motor) of the eye (oculo-). It controls all of the other muscles.