II. Anatomy

  1. neuroCn3oculomotorGrayBB775.gif Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
  2. EyePupillaryReactionNeuroPath.png
  3. EyePupillaryReaction.png

III. Physiology

  1. Parasympathetic fibers follow Cranial Nerve III
    1. Innervates the ciliary Ganglion which in turn supplies sphincter pupillae and ciliaris Muscles
    2. Parasympathetic impulses result in Pupil Constriction
    3. Uncal Herniation (Temporal LobeHerniation) compresses the third nerve
      1. Parasympathetic fibers are most susceptible to injury as they lie on the outside of CN III
      2. Parasympathetic fiber injury results in an ipsilateral pupil that is fixed/unresponsive and dilated
      3. With increasing pressure on Cranial Nerve III, complete oculomotor paralysis occurs
      4. Ultimately contralateral Cranial Nerve 3 involvement ensues
  2. Innervates five extrinsic eye Muscles
    1. Levator palpebrae superioris
    2. Medial rectus
    3. Superior rectus
    4. Inferior rectus
    5. Inferior oblique

IV. Course

  1. Nucleii
    1. Nucleii are located in the floor of Cerebral Aqueduct at the level of the Midbrain
    2. Oculomotor Nucleus
      1. Origin of the eye somatic motor fibers that innervate five extrinsic eye Muscles
      2. Subdivided into focus for each eye Muscle
    3. Edinger-Westphal Nucleus
      1. Origin of the visceral motor fibers that innervate pupillary sphincter and ciliary Muscles
      2. Slightly medial to the Oculomotor Nucleus
  2. Course
    1. As with all other Cranial Nerves (except CN 4), fibers remain ipsilateral (do not cross over)
    2. Nerve courses between Superior Cerebellar Artery and Posterior Cerebral Artery
    3. Forward and lateral to Posterior Clinoid process
    4. Cavernous Sinus lateral wall
    5. Enters orbit via superior orbital fissure

V. Exam

  1. CN III Palsy Findings
    1. eye_eom.png
    2. Eye Deviation inferolaterally (eye is "down and out")
    3. Eyelid Ptosis
  2. Unilateral Pupil Paralysis (Blown Pupil or fixed, non-reactive dilated pupil)
    1. See Unilateral Mydriasis
    2. Increased Intracranial Pressure
    3. Subarachnoid Hemorrhage
  3. Oculomotor Nerve Palsy with pupil involvement
    1. May be due to expanding Cerebral Aneurysm (esp. Posterior Communicating Artery)
  4. Oculomotor Nerve Palsy with pupil sparing
    1. Seen as complication with Diabetes Mellitus

VI. References

  1. Gilman (1989) Manter and Gatz Essentials of Neuroanatomy and Neurophysiology, Davis, p. 87-113
  2. Goldberg (2014) Clinical Neuroanatomy, p. 24-39
  3. Netter (1997) Atlas Human Anatomy, ICON Learning, p. 110-129

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Related Studies

Ontology: Oculomotor nerve structure (C0028864)

Definition (FMA) Cranial nerve which connects the midbrain to the extra-ocular and intra-ocular muscles.
Definition (UWDA) Cranial nerve which connects the midbrain to the extra-ocular and intra-ocular muscles.
Definition (NCI_CDISC) The third cranial nerve.
Definition (MSH) The 3d cranial nerve. The oculomotor nerve sends motor fibers to the levator muscles of the eyelid and to the superior rectus, inferior rectus, and inferior oblique muscles of the eye. It also sends parasympathetic efferents (via the ciliary ganglion) to the muscles controlling pupillary constriction and accommodation. The motor fibers originate in the oculomotor nuclei of the midbrain.
Definition (CSP) third cranial nerve; sends motor fibers to the levator muscles of the eyelid and to the superior rectus, inferior rectus, and inferior oblique muscles of the eye; sends parasympathetic efferents (via the ciliary ganglion) to the muscles controlling pupillary constriction and accommodation; motor fibers originate in the oculomotor nuclei of the midbrain.
Concepts Body Part, Organ, or Organ Component (T023)
MSH D009802
SnomedCT 56193007
English Nerve, Oculomotor, Nerves, Oculomotor, Oculomotor Nerve, Oculomotor Nerves, Cranial Nerve III, Cranial Nerve, Third, Cranial Nerves, Third, Nerve, Third Cranial, Nerves, Third Cranial, Third Cranial Nerve, Third Cranial Nerves, cranial nerve III, Oculomotor nerve [III], Nervus oculomotorius [III], Oculomotor nerve tree, cranial nerve iii, oculomotor nerves, cranial iii nerve, Cranial Nerve IIIs, third cranial nerve, 3n, oculomotor nerve, Nervus oculomotorius, OCULOMOTOR NERVE, Nervus Oculomotorius, Nerve IIIs, Oculomotorius, Nervus, Nerve III, Third cranial nerve, Oculomotor nerve, Cranial nerve III, Oculomotor nerve structure (body structure), Oculomotor nerve structure, Oculomotor nerve, NOS
French Troisième paire crânienne, Nerf oculomoteur, Nerf crânien III, Nerf moteur oculaire commun, Troisième nerf crânien, Nerf oculo-moteur, Nerf crânien 3
Swedish Ögonrörelsenerv
Czech nervus oculomotorius, okohybný nerv, III. hlavový nerv
Finnish Silmän liikehermo
Russian GLAZODVIGATEL'NYI NERV, TRETII CHEREPNOI NERV, ГЛАЗОДВИГАТЕЛЬНЫЙ НЕРВ, ТРЕТИЙ ЧЕРЕПНОЙ НЕРВ
German DRITTER HIRNNERV, Hirnnerv III, III. Hirnnerv, Nervus oculomotorius
Italian Nervo cranico III, Terzo nervo cranico, Nervo oculomotore
Croatian OKULOMOTORNI ŽIVAC
Latvian Acs kustību nervs
Polish Nerw okoruchowy, Nerw III
Japanese 動眼神経, 眼球運動神経, 第3脳神経
Norwegian 3. hjernenerve, Nervus oculomotorius, Øyets bevegelsesnerve, Okulomotorisk nerve, Hjernenerve 3
Spanish III Par Craneal, Nervio Craneal III, III par craneal, estructura del nervio oculomotor (estructura corporal), estructura del nervio oculomotor, nervio craneal III, nervio motor ocular, nervio oculomotor, tercer par craneal, tercer par craneano, III Nervio Craneal, Nervio Oculomotor, Tercer Nervio Craneal
Portuguese III Par Craniano, III Nervo Craniano, Nervo Craniano III, Nervo Oculomotor, Terceiro Nervo Craniano
Dutch IIIe hersenzenuw, Nervus cranialis III, Nervus oculomotorius

Ontology: Oculomotor Nerve Paralysis (C0028866)

Definition (MSH) Diseases of the oculomotor nerve or nucleus that result in weakness or paralysis of the superior rectus, inferior rectus, medial rectus, inferior oblique, or levator palpebrae muscles, or impaired parasympathetic innervation to the pupil. With a complete oculomotor palsy, the eyelid will be paralyzed, the eye will be in an abducted and inferior position, and the pupil will be markedly dilated. Commonly associated conditions include neoplasms, CRANIOCEREBRAL TRAUMA, ischemia (especially in association with DIABETES MELLITUS), and aneurysmal compression. (From Adams et al., Principles of Neurology, 6th ed, p270)
Concepts Disease or Syndrome (T047)
MSH D015840
ICD10 H49.0
SnomedCT 12900003, 30764004, 388980004
English Oculomotor Nerve Palsies, Oculomotor Nerve Palsy, Oculomotor Nerve Paralyses, Oculomotor Nerve Paralysis, Palsies, Oculomotor Nerve, Palsies, Third-Nerve, Palsy, Oculomotor Nerve, Palsy, Third-Nerve, Paralyses, Oculomotor Nerve, Paralyses, Third-Nerve, Paralysis, Third-Nerve, Third Nerve Palsy, Third Nerve Paralysis, Third-Nerve Palsies, Third-Nerve Palsy, Third-Nerve Paralyses, Third-Nerve Paralysis, CRANIAL THIRD NERVE PARALYSIS, OCULOMOTOR NERVE PARALYSIS, Paralysis, Oculomotor Nerve, Third [oculomotor] nerve palsy, CRANIAL NERVE III DIS, THIRD CRANIAL NERVE DIS, OCULOMOTOR NERVE DIS, third cranial nerve palsy, third cranial nerve palsy (diagnosis), Cranial third nerve paralysis, IIIrd nerve palsy, IIIrd nerve paralysis, Oculomotor nerve paralysis, Third nerve paralysis, Cranial Nerve III Diseases, Third Cranial Nerve Diseases, Nerve Disease, Oculomotor, Nerve Diseases, Oculomotor, Oculomotor Nerve Disease, Oculomotor Nerve Diseases, Nerve Disorder, Oculomotor, Nerve Disorders, Oculomotor, Oculomotor Nerve Disorder, Oculomotor Nerve Disorders, Nerve Palsies, Oculomotor, Nerve Palsy, Oculomotor, Nerve Paralyses, Oculomotor, Nerve Paralysis, Oculomotor, Neuropathies, Oculomotor, Neuropathy, Oculomotor, Oculomotor Neuropathies, Oculomotor Neuropathy, Oculomotor Nerve Diseases [Disease/Finding], oculomotor nerve paralysis, cranial nerve paralysis third, oculomotor nerve palsy, third nerve palsy, third nerve paralysis, paralysis third cranial nerve, nerve iii palsy, iii nerve palsy, nerve palsies third, Third cranial nerve disorder, Oculomotor nerve disease, Oculomotor nerve disorder, Third cranial nerve paralysis, Third cranial nerve disease, Third cranial nerve paralysis (disorder), 3rd nerve palsy, III nerve palsy, Oculomotor nerve palsy, Third nerve palsy, n.oculomotorius; paralysis, paralysis; cranial nerve, third, paralysis; oculomotor nerve, Third cranial nerve paralysis, NOS, IIIrd Nerve Paralysis, Palsy;III nerve (oculomotor)
German OKULOMOTORIUSPARALYSE, okulomotorische Nervenlaehmung, Laehmung des dritten Hirnnervs, III. Nerv Laehmung, HIRNNERV-III-LAEHMUNG, Laehmung des N. oculomotorius [III. Hirnnerv], KRANKHEITEN DES HIRNNERVS 03, Laehmung des III. Hirnnervs, Dritter Hirnnerv-Paralyse, Okulomotoriusparalyse, Okulomotoriusparese, Parese, Okulomotorius-, Dritter-Hirnnerv-Parese, Nervus-oculomotorius-Krankheiten, Krankheiten des III. Hirnnervs, Lähmung, Okulomotorius-
Italian Paralisi del III nervo cranico, Paralisi del nervo oculomotore, Paralisi del terzo nervo cranico, Neuropatia oculomotoria, Malattie del nervo oculomotore
Dutch oculomotorische zenuwparalyse, derde hersenzenuwverlamming, derde zenuwparalyse, IIIde zenuwverlamming, n.oculomotorius; paralyse, paralyse; hersenzenuw, derde, paralyse; nervus oculomotorius, Verlamming van derde hersenzenuw [n. oculomotorius], IIIde zenuwparalyse, Derdehersenzenuwverlamming, Nervus-oculomotoriusziekte, Nervus-oculomotoriusziekten, Verlamming van de derde hersenzenuw, Ziekte, nervus-oculomotorius-, Ziekten, nervus-oculomotorius-
French Paralysie du troisième nerf crânien, Paralysie du troisième nerf, Paralysie du IIIe nerf, Paralysie du nerf oculomoteur, PARALYSIE DES NERFS OCULOMOTEURS, PARALYSIE TROISIEME NERF CRANIEN, Paralysie du nerf moteur oculaire commun (IIIème), Affections du nerf moteur oculaire commun, Atteintes de la 3ème paire crânienne, Atteintes de la IIIème paire crânienne, Atteintes de la troisième paire crânienne, Atteintes du nerf moteur oculaire commun, Paralysie du III, Paralysie du nerf moteur oculaire commun
Portuguese Paralisia do III nervo craniano, Paralisia de nervo oculomotor comum, PARALISIA DO TERCEIRO NERVO CRANI, PARALISIA DOS NERVOS OCULOMOTORES, Doenças do III Par Craniano, Paralisia do Terceiro Par Craniano, Paralisia do III nervo, Doenças do III Nervo Craniano, Doenças do Nervo Oculomotor, Paralisia do Terceiro Nervo
Spanish Parálisis del tercer par craneal, Parálisis del tercer par, Parálisis del nervio oculomotor, PARALISIS NERVIO OCULOMOTOR, PARALISIS TERCER PAR CRANEAL, parálisis del tercer nervio craneal, parálisis del tercer nervio craneal (concepto no activo), parálisis del tercer nervio craneano, Enfermedades Craneales del III Nervio, Enfermedades del III Par Craneal, Parálisis del Tercer Par Craneal, Parálisis del III par craneal, Enfermedades del III Nervio Craneal, Enfermedades del Nervio Oculomotor, Parálisis del Tercer Nervio
Japanese 第3脳神経麻痺, 動眼神経麻痺, ダイ3ノウシンケイマヒ, ドウガンシンケイマヒ, 眼球運動神経疾患, 動眼神経疾患, 眼球運動神経麻痺, 第3神経麻痺, 第3神経疾患, 第III神経疾患, 第III神経麻痺, 第三神経疾患, 第三神経麻痺
Swedish Ögonmuskelsjukdomar
Finnish Silmän liikehermon sairaudet
Russian GLAZODVIGATEL'NOGO NERVA BOLEZNI, GLAZODVIGATEL'NOGO NERVA PAREZ, CHEREPNOGO III NERVA PARALICH, CHEREPNOGO III NERVA PAREZ, ГЛАЗОДВИГАТЕЛЬНОГО НЕРВА БОЛЕЗНИ, ГЛАЗОДВИГАТЕЛЬНОГО НЕРВА ПАРЕЗ, ЧЕРЕПНОГО III НЕРВА ПАРАЛИЧ, ЧЕРЕПНОГО III НЕРВА ПАРЕЗ
Czech Obrna nervus oculomotorius, Obrna III.hlavového nervu, Obrna třetího hlavového nervu, Paralýza III.hlavového nervu, nervus oculomotorius - nemoci, nemoci nervu oculomotorius, paralýza nervu oculomotorius, nemoci okohybného nervu, nemoci III. hlavového nervu, poruchy okohybného nervu
Korean 제3뇌[눈돌림] 신경마비
Polish Porażenie nerwu III, Choroby nerwu okoruchowego
Hungarian III. ideg paresis, Nervus III. paralysis, Nervus Oculomotorius paralysis, III. agyideg paralysis
Norwegian Sykdommer i okulomotorisk nerve, Lammelse av nervus oculomotorius, Okulomotorisk nerve-sykdommer, Okulomotorisk nevropati, Lammelse i 3. hjernenerve, 3. hjernenerve-parese, Sykdom i 3. hjernenerve, Sykdommer i nervus oculomotorius

Ontology: Edinger Westphal nucleus (C0228416)

Definition (MSH) Nucleus in the oculomotor nuclear complex associated with oculomotor activities and stress adaptation.
Concepts Body Part, Organ, or Organ Component (T023)
MSH D065839
SnomedCT 280162006, 62088007
English Parvocellular oculomotor nucleus, Accessory oculomotor nucleus, Oculomotor nucleus, parvocellular part, edinger-westphal nucleus, Edinger-Westphal nucleus of oculomotor nerve, parvocellular oculomotor nucleus, oculomotor nucleus, parvicellular part, oculomotor nucleus, parvocellular part, accessory oculomotor nucleus, PC3, Edinger Westphal nucleus, Nuclei accessorii nervi oculomtorii (Edinger-Westphal), Nucleus rostralis nervi oculomotorii, Nucleus Westphal-Edinger, Nucleus nervi oculomotorii Edinger-Westphal, Nucleus nervi oculomotorii parvocellularis, Edinger-Westphal nucleus (body structure), Edinger Westphal, Nucleus, Westphal, Nucleus Edinger, Nucleus Edinger Westphal, Edinger Westphal Nucleus, Edinger Westphals, Nucleus, Nucleus, Edinger-Westphal, Parvocellular Oculomotor Nucleus, Nucleus, Accessory Oculomotor, Edinger-Westphal Nucleus, Accessory Oculomotor Nucleus, Oculomotor Nucleus, Accessory, Westphals, Nucleus Edinger, Nucleus, Parvocellular Oculomotor, Oculomotor Nucleus, Parvocellular, Nucleus Edinger Westphals, Edinger Westphal nucleus (body structure), Edinger-Westphal nucleus
Spanish núcleo de Edinger - Westphal (estructura corporal), núcleo de Edinger - Westphal, núcleo de Edinger Westphal (estructura corporal), núcleo de Edinger Westphal

Ontology: Oculomotor nucleus (C0228686)

Definition (MSH) A collection of nuclei in the midbrain tegmentum for the OCULOMOTOR NERVE fibers.
Definition (CSP) somatic motor nucleus in the midbrain whose fibers enter the oculomotor nerve to supply the levator palpebrae muscle and all the extraocular eye muscles except the superior oblique and lateral rectus muscles.
Concepts Body Part, Organ, or Organ Component (T023)
MSH D065838
SnomedCT 59473007
English oculomotor nuclei, Set of oculomotor nuclei, Oculomotor nuclear complex, Oculomotor nuclei, Nucleus of oculomotor nerve, Nucleus of third cranial nerve, Oculomotor nuclei set, oculomotor nucleus, nucleus of oculomotor nerve, 3, oculomotor nuclear complex, Nucleus nervi oculomotorii, Nucleus oculomotorius, Oculomotor Nuclear Complex, Oculomotor Nucleus, Nervi Oculomotorii, Nucleus, Nuclear Complex, Oculomotor, Nucleus Oculomotorius, Nucleus Nervi Oculomotorius, Oculomotorius, Nucleus, Nucleus Nervi Oculomotorii, Nervi Oculomotorius, Nucleus, Nucleus, Oculomotor, Oculomotorii, Nucleus Nervi, Oculomotorius, Nucleus Nervi, Third cranial nerve nucleus, Oculomotor nucleus structure (body structure), Oculomotor nucleus structure, Oculomotor nucleus, nucleus nervi oculomotorii, nucleus oculomotorius
Spanish estructura del núcleo oculomotor (estructura corporal), estructura del núcleo oculomotor, núcleo del III par craneal, núcleo del nervio motor ocular, núcleo del tercer nervio craneal, núcleo del tercer par craneal, núcleo oculomotor