Medial rectus muscle

The medial rectus muscle is a muscle in the orbit.

As with most of the muscles of the orbit, it is innervated by the inferior division of the oculomotor nerve (Cranial Nerve III).

This muscle shares an origin with several other extrinsic eye muscles, the anulus tendineus, or common tendon.

It is the largest of the extraocular muscles and its only action is adduction of the eyeball. Its function is to bring the pupil closer to the midline of the body. It is tested clinically by asking the patient to look medially.

Additional images

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  Eye movement of lateral rectus muscle, superior view

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  Eye movement of medial rectus muscle, superior view

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  Eye movement of inferior rectus muscle, superior view

• Eye movements elevators.jpg

  Eye movement of superior rectus muscle, superior view

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  Eye movement of superior oblique muscle, superior view

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  Eye movement of inferior oblique muscle, superior view

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  Anterior view

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  Horizontal section of the eyeball.

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  Dissection showing origins of right ocular muscles, and nerves entering by the superior orbital fissure.

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  Vestibulo-ocular reflex

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  Medial rectus muscle

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  Medial rectus muscle

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  Extrinsic eye muscle. Nerves of orbita. Deep dissection.

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  Extrinsic eye muscle. Nerves of orbita. Deep dissection.

• Slide2abaa.JPG

  Extrinsic eye muscle. Nerves of orbita. Deep dissection.

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  Extrinsic eye muscle. Nerves of orbita. Deep dissection.

• Slide4abab.JPG

  Extrinsic eye muscle. Nerves of orbita. Deep dissection.

• Slide5abab.JPG

  Extrinsic eye muscle. Nerves of orbita. Deep dissection.

External links

• -1476001712 at GPnotebook
• Anatomy figure: 29:01-06 at Human Anatomy Online, SUNY Downstate Medical Center
• lesson3 at The Anatomy Lesson by Wesley Norman (Georgetown University) (orbit4)
• Diagram at howstuffworks.com