•LPS and Orbicularis oculi

Dr.Samia FatimaBY -

Levator Palpebrae Superioris

Origin: lesser wing of sphenoid anterior to optic canal

• Insertion: Anterior surface of tarsal plate,a few fibres to skin and superior conjuctival fornix

Innervation: Occulomotor nerve(III)_superior branch

• Function : elevation of upper eyelid by contraction

Unique feature of LPS is a collection of smooth muscle fibres passes from its

inferior surface to upper edge of superior tarsus.

This group of smooth muscle fibres(sup.tarsal muscle) help maintain eyelid elevation and are innervated by

postganglionic sympathetic fibres from sup.cervical ganglion

ORBICULARIS OCULI

Orbicularis Oculi

• Palpebral part Origin: medial palpebral ligamentInsertion: lateral palpebral rapheInnervation: facial nerve (VII)Function: closes the eyelids gently

2 parts Palpebral part Orbital part

• Orbital partOrigin: nasal part of frontal bone;frontal process of maxilla:medial palpebral ligamentInsertion: Fibres from an uninterrupted ellipse around orbitInnervation: facial nerve (VII)Function: closes the eyelids forcefully