- Medial rectus muscle
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Medial rectus 
Rectus muscles:
2 = superior, 3 = inferior, 4 = medial, 5 = lateral
Oblique muscles: 6 = superior, 8 = inferior
Other muscle: 9 = levator palpebrae superioris
Other structures: 1 = Annulus of Zinn, 7 = Trochlea, 10 = Superior tarsus, 11 = Sclera, 12 = Optic nerve
Figure showing the mode of innervation of the Recti medialis and lateralis of the eye. Latin musculus rectus medialis bulbi Gray's subject #227 1022 Origin annulus of Zinn at the orbital apex Insertion 5.5 mm medial to the limbus Artery Nerve inferior division of the oculomotor nerve Actions adducts the eyeball (makes it move inwards) 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
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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
credit: Patrick J. Lynch-
Horizontal section of the eyeball.
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Dissection showing origins of right ocular muscles, and nerves entering by the superior orbital fissure.
External links
- LUC mr
- -1476001712 at GPnotebook
- SUNY Figs 29:01-06
- medial+rectus+muscle at eMedicine Dictionary
- lesson3 at The Anatomy Lesson by Wesley Norman (Georgetown University) (orbit4)
- Diagram at howstuffworks.com
List of muscles of head and neck: the head (TA A04.1, GA 4.378) Extraocular (CN III, IV, VI) oblique (inferior, superior) · rectus (superior, inferior, medial, lateral) · levator palpebrae superioris (superior tarsal)Mastication (CN V3) masseter · temporalis (sphenomandibularis) · pterygoid (lateral, medial)
fascia: Masseteric fascia · Temporal fascia · Deep portion: cementomaxillary tendon · Superficial portion: cementomandibular tendonFacial (CN VII) levator anguli oris · levator labii superioris · zygomaticus (major, minor)
orbicularis oris · risorius · buccinator
depressor anguli oris · depressor labii inferioris · mentalisPalate/fauces (CN IX, X, XI)
(except TVP=V3)veli palatini (tensor, levator) · musculus uvulae · palatopharyngeus (to pharynx) · palatoglossus (to tongue)Tongue (CN XII) extrinsic (genioglossus, hyoglossus/chondroglossus, styloglossus, and palatoglossus) · intrinsic (superior longitudinal, inferior longitudinal, transverse, vertical)Categories:- Muscles of the head and neck
- Eye anatomy
- Muscle stubs
- Eye stubs
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