Medial Rectus Muscle of the Eye (musculus rectus medialis bulbi) – Human Anatomy | Kenhub

Medial Rectus Muscle of the Eye (musculus rectus medialis bulbi) – Human Anatomy | Kenhub


Hello again everyone! This is Matt from Kenhub, and in this tutorial,
we will be looking at the medial rectus muscle of the eye, its origin and insertion, function
and innervation and blood supply. The medial rectus muscle is one of the six
extraocular muscles that control eye movements. This muscle is located on the medial aspect
of the eyeball. It is also the largest of the extraocular
muscles and stronger than its antagonistic pairing – the lateral rectus muscle. The medial rectus muscle along with the other
rectus muscles originates from the common tendinous ring also known as the annulus of
Zinn which is located at the apex of the orbit around the optic canal. The annulus of Zinn is formed by the tendons
of the four rectus muscles – medial, lateral, superior and inferior. The medial rectus muscle inserts onto the
anteromedial surface of the eye. When the eye is at a neutral position, contraction
of the medial rectus muscle moves the pupil of the eye inward medially towards the nose. This movement is called adduction. Innervation of the medial rectus muscle is
provided by the inferior branch of the oculomotor nerve – the third cranial nerve. The oculomotor nerve in green is shown here
from a lateral view. The continuation of this branch here innervates
the medial rectus muscle on the medial aspect of the eye not visible in this image. The medial rectus muscle receives arterial
blood supply from two branches of the anterior ciliary arteries which are derived from the
ophthalmic artery. In this image, only one of these branches
is visible indicated here. This tutorial might be over, but there are
more videos you can watch related to this topic. You can also subscribe to our YouTube channel
or go to our website where you’ll find fun quizzes, related articles, and atlas sections
– all you need to kick some gluteus maximus in anatomy and histology. I’ll see you soon! https://www.kenhub.com

3 Replies to “Medial Rectus Muscle of the Eye (musculus rectus medialis bulbi) – Human Anatomy | Kenhub”

  1. Hello, hello! It has been a joy working on our videos about the eye muscles. Hopefully we were able to simplify this topic for you. Even without becoming a Kenhub Premium member, you can still learn anatomy with us. So check out this free article on the extraocular muscles: https://khub.me/qzfvk Thanks for watching!

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