Levator palpebrae superioris muscle

Levator palpebrae superioris
Rectus muscles:
2 = superior, 3 = inferior, 4 = medial, 5 = lateral
Oblique muscles: 6 = superior, 8 = inferior
Other muscle: 9 = levator palpebrae superioris
Other structures: 1 = Annulus of Zinn, 7 = Trochlea, 10 = Superior tarsus, 11 = Sclera, 12 = Optic nerve
The levator palebrae superioris can be seen here, travelling above the superior rectus muscle, and ending at the upper eyelid.
Details
OriginInferior surface of lesser wing of sphenoid
InsertionSuperior tarsal plate and skin of upper eyelid
ArteryMuscular branches of ophthalmic artery and supraorbital artery
NerveSuperior division of oculomotor nerve
ActionsElevation of upper eyelid
AntagonistPalpebral part of orbicularis oculi muscle
Identifiers
Latinmusculus levator palpebrae superioris
TA98A15.2.07.020
TA22052
FMA49041
Anatomical terms of muscle

The levator palpebrae superioris (Latin: elevating muscle of upper eyelid) is the muscle in the orbit that elevates the upper eyelid.

Structure

The levator palpebrae superioris originates from inferior surface of the lesser wing of the sphenoid bone, just above the optic foramen. It broadens and decreases in thickness (becomes thinner) and becomes the levator aponeurosis. This portion inserts on the skin of the upper eyelid, as well as the superior tarsal plate. It is a skeletal muscle. The superior tarsal muscle, a smooth muscle, is attached to the levator palpebrae superioris, and inserts on the superior tarsal plate as well.

Blood supply

The levator palebrae superioris receives its blood supply from branches of the ophthalmic artery, specifically, muscular branches and the supraorbital artery. Blood is drained into the superior ophthalmic vein.

Nerve supply

The levator palpebrae superioris receives motor innervation from the superior division of the oculomotor nerve. The smooth muscle that originates from its undersurface, called the superior tarsal muscle is innervated by postganglionic sympathetic axons from the superior cervical ganglion.

Function

The levator palpebrae superioris elevates the upper eyelid.

Clinical significance

Damage to this muscle or its innervation can cause ptosis, which is drooping of the eyelid. Lesions in CN III can cause ptosis, because without stimulation from the oculomotor nerve the levator palpebrae cannot oppose the force of gravity, and the eyelid droops.

Ptosis can also result from damage to the adjoining superior tarsal muscle or its sympathetic innervation. Such damage to the sympathetic supply occurs in Horner's syndrome and presents as a partial ptosis. It is important to distinguish between these two very different causes of ptosis. This can usually be done clinically without issue, as each type of ptosis is accompanied by other distinct clinical findings.

The ptosis seen in paralysis of the levator palpebrae superioris is usually more pronounced than that seen due to paralysis of the superior tarsal muscle.

Additional images

See also


This page was last updated at 2024-03-26 11:37 UTC. Update now. View original page.

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