File:Gray0379.jpg

Fig. 379. Left orbicularis oculi

(seen from behind)

• Muscles - (of the eyelids) Levator palpebræ superiors, Orbicularis oculi and Corrugator.
• Nerve - Orbicularis oculi and Corrugator are supplied by the facial nerve.

The Orbicularis oculi (Orbicularis palpebrarum) (Fig. 379) 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. 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 raphé. 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 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 (Fig. 379). 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 medial palpebral ligament (tendo oculi), about 4 mm. in length and 2 mm. in breadth, is attached to the frontal process of the maxilla in front of the lacrimal groove. Crossing the lacrimal sac, it divides into two parts, upper and lower, each attached to the medial end of the corresponding tarsus. As the ligament crosses the lacrimal sac, a strong aponeurotic lamina is given off from its posterior surface; this expands over the sac, and is attached to the posterior lacrimal crest.

The lateral palpebral raphé is a much weaker structure than the medial palpebral ligament. It is attached to the margin of the frontosphenoidal process of the zygomatic bone, and passes medialward to the lateral commissure of the eyelids, where it divides into two slips, which are attached to the margins of the respective tarsi.

The Corrugator (Corrugator supercilii) is a small, narrow, pyramidal muscle, placed at the medial end of the eyebrow, beneath the Frontalis and Orbicularis oculi. It arises from the medial end of the superciliary arch; and its fibers pass upward and lateralward, between the palpebral and orbital portions of the Orbicularis oculi, and are inserted into the deep surface of the skin, above the middle of the orbital arch.

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iTunes link | iBooks Store Description - an extract of the embryology content from Anatomy of the Human Body By Henry Gray Philadelphia: Lea & Febiger, 1918. Releases First Edition - Jan 2012 Second Edition - March 2012 Repaired formatting and image display issues related to Pad rotated display and minor editing issues. Print length 169 pages, 41.6 MB, Language English. The current website also includes numerous images from this textbook, see Anatomy of the Human Body by Henry Gray and Category:Gray's 1918 Anatomy. Note the also Historic Disclaimer.

Reference

Gray H. Anatomy of the human body. (1918) Philadelphia: Lea & Febiger.

Cite this page: Hill, M.A. (2024, April 19) Embryology Gray0379.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Gray0379.jpg

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