Inferior rectus muscle of the eye – Origin, Insertion, Function – Anatomy | Kenhub

Inferior rectus muscle of the eye – Origin, Insertion, Function – Anatomy | Kenhub


Hello everyone! This is Matt from Kenhub, and in this tutorial,
we will discuss one of the six extraocular muscles of the eye – the inferior rectus
muscle. The inferior rectus muscle is one of the six
extraocular muscles of the eye that control eye movement. The inferior rectus is a straight muscle that
originates from the common tendinous ring also known as the annulus of Zinn which is
found at the apex of the orbit around the optic canal indicated here by an arrow. The common tendinous ring is formed by the
tendons of the rectus muscles. The inferior rectus muscle inserts onto the
anterior, inferior surface of the eye on the sclera – the white of the eye – about
six millimeters posterior to the corneal limbus indicated by the green circle which is the
border between the cornea and the sclera. When the eye is in a neutral position, the
inferior rectus muscle is responsible for the following movements of the eye: Extorsion
which is outward or lateral rotation, adduction which is medial movement towards the midline,
and depression which is movement inferiorly. During adduction of the eye, the inferior
rectus muscle is again responsible for depression, extorsion and adduction of the eye. During abduction, however, which is the lateral
movement of the eye away from the midline, the inferior rectus muscle is responsible
for the depression of the eye. Nerve supply to the inferior rectus muscle
is provided by the inferior branch of the oculomotor nerve – cranial nerve three – highlighted
in green in the image. The ocular motor nerve innervates four of
the six extraocular muscles. Arterial blood supply to the inferior rectus
is provided by muscular branches of the ophthalmic artery shown in green and specifically the
branches running inferiorly. Additionally, the inferior rectus muscle receives
a branch of the infraorbital artery. The infraorbital artery is highlighted in
green in the image. 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 “Inferior rectus muscle of the eye – Origin, Insertion, Function – Anatomy | Kenhub”

  1. Hi everyone! Hope you enjoyed watching our video on the anatomy of the inferior rectus muscle. Please let us know what you would like us to cover on the next videos. Are you ready to test your knowledge? Check out our quiz on the muscles of the orbit available to premium members: https://khub.me/u76mj Good luck!

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