Orbicularis oculi muscle

Orbicularis oculi muscle is a muscle in the face that closes the eyelids. It is one of the two major components of the eyelids, the other being the levator palpebrae superioris muscle. The orbicularis oculi muscle is not just a single muscle, but a group of muscles that work together to close the eye. This muscle is also responsible for the spontaneous blink reflex, which helps to keep the eyes moist and protected.

Anatomy

The orbicularis oculi muscle is divided into three parts: the orbital part, the palpebral part, and the lacrimal part. The orbital part is responsible for forcefully closing the eye, as in a squint. The palpebral part is responsible for the spontaneous blink reflex. The lacrimal part helps to drain tears from the eye by pulling on the lacrimal sac, causing tears to flow into the nasolacrimal duct.

Function

The primary function of the orbicularis oculi muscle is to close the eye. This can happen voluntarily, as in a blink or a squint, or involuntarily, as in the spontaneous blink reflex. This reflex helps to keep the eyes moist and protected from dust and other particles. The muscle also helps to drain tears from the eye.

Clinical significance

Damage to the orbicularis oculi muscle can result in a number of conditions, including blepharospasm, a condition where the eyelids twitch or close involuntarily, and lagophthalmos, a condition where the person is unable to close their eyes completely. Treatment for these conditions can include botulinum toxin injections, which can help to relax the muscle and reduce symptoms.

See also

• Facial muscles
• Blepharospasm
• Lagophthalmos

Orbicularis oculi muscle Resources
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References

External links

• Orbicularis oculi muscle at PubMed Health
• Orbicularis oculi muscle at AnatomyExpert