orbicularis oculi

Introduction

Facial muscle of the eyelids, consisting of 3 parts:

• orbital or external part
  • origin: frontal process of maxilla & nasal process of frontal bone
  • encirles the aperature of the orbit
  • insertion: near the origin
  • tightly closes eye
• palpebral or internal part
  • origin: medial palpebral ligament
  • passes through upper & lower eyelids
  • insertion: lateral palbebral raphe
  • gently closes eye
• lacrimal part (tensor tarsi, Durverney or Horner muscle)
  • origin: posterior lacrimal crest
  • passes across lacrimal sac & joins palpebral part

Action

• closes eye
• wrinkles forehead vertically

Innervation

• zygomatic & temporal branches of the facial nerve (CN VII)

More general terms

• skeletal muscle (voluntary muscle)