orbicularis oculi (muscle)

or·bic·u·la·ris oc·u·li (mus·cle)

[TA] facial muscle of eyelids; consists of three portions: orbital part, or external portion, which arises from frontal process of maxilla and nasal process of frontal bone, encircles aperture of orbit, and is inserted near origin; palpebral part, or internal portion, which arises from medial palpebral ligament, passes through each eyelid, and is inserted into lateral palpebral raphe; lacrimal part (tensor tarsi muscle, Duverney or Horner muscle) arises from posterior lacrimal crest and passes across lacrimal sac to join palpebral portion; action, closes eye, wrinkles forehead vertically; nerve supply, zygomatic and temporal branches of facial. Synonym(s): musculus orbicularis oculi [TA], musculus orbicularis palpebrarum, orbicular muscle of eye, sphincter oculi