Medial rectus at a glance
- What it is
- An extraocular muscle on the medial wall of the orbit.
- Location
- Origin: common tendinous ring. Insertion: medial sclera.
- Function
- Adducts the eyeball (turns it inward).
- Body system
- Muscular · paired (left and right)
- FMA ID
- FMA49057 (Foundational Model of Anatomy)
Key facts
- Innervation: oculomotor nerve (CN III)
- It is the largest and strongest extraocular muscle.
- It is tested by asking the patient to look toward the nose.
- Blood supply: medial muscular branch of the ophthalmic artery
Clinical relevance
In an oculomotor nerve palsy it is paralysed, so the eye drifts outward (exotropia).
Structures next to the medial rectus
The nearest named structures in the 3D model, measured from the centre of each part:
- Long ciliary nerve · nervous
- Anterior ethmoidal nerve · nervous
- Inferior rectus · muscular
- Nasociliary nerve · nervous
- Superior rectus · muscular
- Superior oblique · muscular
- Ciliary ganglion · nervous
- Inferior branch of oculomotor nerve · nervous
- Levator palpebrae superioris · muscular
- Superior branch of oculomotor nerve · nervous
References
- Foundational Model of Anatomy: Medial rectus (FMA49057). EMBL-EBI Ontology Lookup Service.
- OpenStax. Anatomy and Physiology 2e, §11.2 Naming Skeletal Muscles. Rice University, 2022.
- Mitsuhashi N. et al. (2009). BodyParts3D: 3D structure database for anatomical concepts. Nucleic Acids Research 37, D782–D785. Data © The Database Center for Life Science, CC BY 4.0.
Related anatomy
Explore the whole body in the interactive 3D human anatomy model, or browse the A–Z list of human structures.