Orbicularis oculi muscle
| Orbicularis oculi muscle | |
|---|---|
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| Details | |
| Origin | frontal bone; medial palpebral ligament; lacrimal bone |
| Insertion | lateral palpebral raphe |
| Artery | ophthalmic, zygomatico-orbital, angular |
| Nerve | Temporal (orbital, palpebral) & Zygomatic (lacrimal) branches of Facial Nerve |
| Actions | closes eyelids |
| Antagonist | levator palpebrae superioris |
| Identifiers | |
| Latin | musculus orbicularis oculi also musculus orbicularis palpebrarum |
| TA | A04.1.03.013 |
| FMA | 46779 |
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Anatomical terms of muscle
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The orbicularis oculi is a muscle in the face that closes the eyelids. It arises from the nasal part of the frontal bone, from the frontal process of the maxilla in front of the lacrimal groove, and from the anterior surface and borders of a short fibrous band, the medial palpebral ligament.
From this origin, the fibers are directed lateralward, forming a broad and thin layer, which occupies the eyelids or palpebræ, surrounds the circumference of the orbit, and spreads over the temple, and downward on the cheek.
There are at least 3 clearly defined sections of the orbicularis muscle. However, it is not clear whether the lacrimal section is a separate section, or whether it is just an extension of the Preseptal orbicularis and the Pretarsal orbicularis sections.
The orbital portion is thicker and of a reddish color; its fibers form a complete ellipse without interruption at the lateral palpebral commissure; the upper fibers of this portion blend with the Frontalis and Corrugator.
The palpebral portion of the muscle is thin and pale; it arises from the bifurcation of the medial palpebral ligament, forms a series of concentric curves, and is inserted into the lateral palpebral raphe at the outer canthus (corner) of eye. The palpebral portion contains the Preseptal orbicularis and the Pretarsal orbicularis muscles. The Pretarsal orbicularis is thought to be responsible for the spontaneous blink
The lacrimal part (tensor tarsi) is a small, thin muscle, about 6 mm in breadth and 12 mm in length, situated behind the medial palpebral ligament and lacrimal sac. It arises from the posterior crest and adjacent part of the orbital surface of the lacrimal bone, and passing behind the lacrimal sac, divides into two slips, upper and lower, which are inserted into the superior and inferior tarsi medial to the puncta lacrimalia; occasionally it is very indistinct. The lacrimal orbicularis facilitates the tear pump into the lacrimal sac.
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Wikipedia