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Oculomotor nucleus

The oculomotor nucleus is a small somatic motor nucleus in the midbrain and one of the two nuclei for the oculomotor nerve.

Gross Anatomy

The nucleus is located in the central midbrain at the level of the superior colliculus ventral and medial periaqueductal grey matter. It lies immediately ventral to the smaller Edinger-Westphal nucleus and just cranial to the trochlear nucleus. The nucleus forms a longitudinal paramedian column of somatic motor nuclei along with the trochlear, abducens and hypoglossal nuclei.

Efferent fibers leave the nucleus ventrally joining fibers from the Edinger-Westphal nucleus and pass through the red nucleus and emerge from the medial aspect of the cerebral peduncles.


The somatic motor fibers innervate the striated muscle fibers of the levator palpebrae superioris and four of the six extraocular muscles:

Anatomy: Brain

Anatomy: Brain

Article information

rID: 80966
Section: Anatomy
Synonyms or Alternate Spellings:

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Cases and figures

  • Figure 1
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  • Figure 2: cranial nerve nuclei (illustration)
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  • Figure 3: brainstem motor nuclei - Gray's anatomy illustration
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  • Figure 4: brainstem nuclei: dorsal section - Gray's anatomy illustration
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