flowchart TD A[Interpeduncular fossa of Midbrain] --> B[Oculomotor Nucleus] B -- Somatic motor --> C[Superior ORbital fissure] C --> D[Extraocular muscles] D --> E{Somatic Motor} A --> F[Edinger-Westphal Nucleus] F -- Parasympathetic Efferent --> C C --> G[Ciliary ganglion] G -- Postganglionic parasympathetic fibers --> H{GVE: Sphincter pupillae & Ciliary muscles}
CN III Oculomotor Nerve
Overview
- CN III refers to nerve fibers containing somatic motor fibers running to extraocular muscles of the eye as well as parasympathetic efferent fibers running to the muscles in the lens.
- CN III is myelinated by Schwann cells and is therefore considered part of the PNS.
Pathway
Function
Somatic motor control of Extraocular muscles
- Superior Recti
- Medial Recti
- Inferior Recti
- Inferior Oblique
Parasympathetic efferent to lens
Dysfunction
Clinical Presentation
Diploplia
Ptosis
- levator palpebral ptosis damage to lev palp results in no AP
Mydriasis
- Loss of parasympathetic innervation of Constrictor Pupillae
Down & Out Gaze
References
1.
Gray H. Anatomy of the Human Body. 20th ed. (Lewis WH, ed.). Lea & Febiger; 1918. https://www.bartleby.com/107/
2.
Blumenfeld H. Neuroanatomy Through Clinical Cases. 3rd ed. Oxford university press; 2022.
Citation
For attribution, please cite this work as:
Yomogida N, Kerstein C. CN III Oculomotor
Nerve. https://yomokerst.com/The
Archive/Neuroscience/Neuroanatomy/Cranial
Nerves/CN3_Oculomotor.html