Dorlands
/Elsevier m_22/12550510 | ||
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Origin annulus of Zinn at the orbital apex Insertion 5.5 mm medial to the limbus Nerve inferior division of the oculomotor nerve Actions adducts the eyeball (makes it move inwards) Latin musculus rectus medialis bulbi | ||
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.
References
Medial rectus muscle Wikipedia(Text) CC BY-SA