Head and neck muscles (chewing, facial, and throat muscles)

Levator Palpebrae Superioris

Musculus levator palpebrae superioris

Origin

Lesser wing of the sphenoid bone, above the origin of the superior rectus muscle

Insertion

Skin of the upper eyelid and the superior tarsus via the aponeurosis; the smooth-muscle component (superior tarsal muscle) attaches directly to the tarsus

Function

Elevates the upper eyelid (eyelid opening)

Innervation

Oculomotor nerve (CN III), superior branch; the smooth-muscle component (superior tarsal muscle) receives sympathetic innervation

Movement & chain

Elevates the upper eyelid, driven by CN III; the smooth-muscle component (superior tarsal muscle) provides a small additional, sympathetically driven contribution. No skeletal joint chain is involved.

Palpation

Not directly palpable; situated deeply within the orbital apex superior to superior rectus.

Clinical

Failure produces ptosis (drooping eyelid) in CN III palsy (e.g. from an aneurysm of the posterior communicating artery) or in loss of sympathetic drive (Horner's syndrome, milder ptosis via the superior tarsal muscle).

Segmental innervation

CN III, motor; sympathetic fibers from T1 (superior cervical ganglion) for the superior tarsal muscle.

In clinical practice

Primary upper eyelid elevator (CN III); surgical levator advancement or frontalis sling for severe blepharoptosis and Myasthenia Gravis evaluation.

Region in the model

Head and neck muscles (chewing, facial, and throat muscles)