Muscles of Facial Expression and Extraocular Muscles

All facial muscles are innervated by

facial nerve (CN VII)

Facial expression muscles

frontalis

orbicularis oris

buccinator

orbicularis oculi

Frontalis

Frontalis Action

Raises eyebrows and wrinkles forehead (surprise)

Orbicularis oris

Orbicularis oris Action

Puckers lips

Buccinator

Buccinator Action

Compresses cheeks (blowing)

Orbicularis oculi

Orbicularis oculi Action

Closes eye tightly

Extraocular muscles

Superior rectus

Inferior rectus

Medial rectus

Superior oblique

Lateral rectus

Inferior oblique

Levator palpebrea

Superior Rectus

Superior Rectus Origin

Orbital cavity

Superior Rectus Insertion

Sclera - superiorly

Superior Rectus Innervation

Oculomotor nerve (CN III)

Superior Rectus Action

Elevate pupil

Inferior Rectus

Inferior Rectus Origin

Orbital cavity

Inferior Rectus Insertion

Sclera - Inferiorly

Inferior Rectus Innervation

Oculomotor nerve (CN III)

Inferior Rectus Action

Depress pupil

Medial Rectus

Medial Rectus Origin

Orbital cavity

Medial Rectus Insertion

Sclera - medially

Medial Rectus Innervation

Oculomotor nerve (CN III)

Medial Rectus Action

Adduct pupil

Superior Oblique

Superior Oblique Origin

Orbital cavity

Superior Oblique Insertion

Around trochlea to point posterior to superior rectus

Superior Oblique Innervation

Trochlear nerve (CN IV)

Superior Oblique Action

Turn pupil down and out, rotates pupil medially (top of eye moves medially)

Lateral Rectus

Lateral Rectus Origin

Orbital Cavity

Lateral Rectus Insertion

Sclera - Laterally

Lateral Rectus Innervation

Abducens nerve (CN VI)

Lateral Rectus Action

Abduct pupil

Inferior Oblique

Inferior Oblique Origin

Orbital Cavity

Inferior Oblique Insertion

Point posterior to lateral rectus

Inferior Oblique Innervation

Oculomotor nerve (CN III)

Inferior Oblique Action

Turn pupil up and in, rotates pupil laterally (top of eye moves laterally)

Levator Palpebrea

Levator Palpebrea Origin

Sphenoid bone

Levator Palpebrea Insertion

Skin of the upper eyelid

Levator Palpebrea Innervation

Oculomotor Nerve (CN III)

Levator Palpebrea Action

Elevates upper eyelid

Levator Palpebrea is an exception because

This is an eyelid muscle and is technically not an extraocular eye muscle since it does not move the eye.