Oculomotor, trochlear and abducens nerves (CN III, IV & VI)

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Movements of the eyeball affecting the direction of gaze are controlled by three cranial nerves: the oculomotor (CN III), trochlear (CN IV) and abducens (CN VI) nerves. 

To be more specific, these nerves provide motor supply to the extraocular muscles:

• Oculomotor nerve: superior, medial and inferior recti muscles, as well as the inferior oblique muscle. 
• Trochlear nerve: superior oblique muscle (‘trochlear’ referring to the pulley-like anatomy of this muscle (Latin: trochlea = pulley).
• Abducens nerve: lateral rectus (‘abducens’ refers to abduction of the eye which is achieved by this muscle).

In addition, the oculomotor nerve also provides motor innervation to the levator palpebrae superioris muscle, as well as parasympathetic innervation to the sphincter pupillae and ciliary muscles. Therefore, it also has a role in elevation of the upper eyelid, pupillary constriction and accommodation of the lens.

The following video will help you learn everything about these cranial nerves related to ocular movements: their origins, paths, anatomical relationships as well as their target structures.

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Don’t roll your eyes at this quiz! It’s the most efficient way to solidify your knowledge and will set you up for success in your upcoming cranial nerves exam!

You can also try out a broader approach and really challenge yourself with a custom-made quiz covering all of the cranial nerves!

Browse atlas

Follow the course of each these cranial nerves in the following gallery:

Take a closer look at each structure in the following atlas gallery:

Summary