II. Anatomy

  1. Hypoglossal Nucleus
    1. Originates in Hypoglossal Nucleus, in the Medulla
    2. Exits anterior to the Inferior Olivary Nucleus
      1. All other medulla Cranial Nerves (CN 7, CN 8, CN 9, CN 10) exit posterior to the Inferior Olivary Nucleus
  2. Images
    1. neuroHypoglossalCN12.png
    2. neuroCn12HypoglossalGrayBB795.gifLewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
  3. Course
    1. As with all other Cranial Nerves (except CN 4), fibers remain ipsilateral (do not cross over)
    2. Passes through hypoglossal canal beside foramen magnum
    3. Courses downward with neurovascular structures
      1. Internal Carotid Artery
      2. Jugular Vein
      3. Vagus Nerve (CN 10)
    4. Curves forward behind Mandible to lingual root

III. Physiology

IV. Exam

  1. Patient protrudes Tongue in midline
    1. Unilateral paralysis causes deviation to weak side
    2. Observe for Tremor, atrophy, Fasciculations
  2. Test lingual speech, by having patient say:
    1. "Round the rugged rock the ragged rascal ran"
    2. "Third riding artillery brigade"

V. 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

Calculation (FPnotebook.com: DrBits) Open in New Window

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Related Studies

Ontology: Hypoglossal nerve structure (C0020614)

Definition (NCI) The twelfth cranial nerve. It arises from the hypoglossal nucleus and leads to the tongue.
Definition (NCI_CDISC) The twelfth cranial nerve.
Definition (MSH) The 12th cranial nerve. The hypoglossal nerve originates in the hypoglossal nucleus of the medulla and supplies motor innervation to all of the muscles of the tongue except the palatoglossus (which is supplied by the vagus). This nerve also contains proprioceptive afferents from the tongue muscles.
Definition (CSP) twelfth cranial nerve; originates in the hypoglossal nucleus of the medulla and supplies motor innervation to all of the muscles of the tongue except the palatoglossus (which is supplied by the vagus); also contains proprioceptive afferents from the tongue muscles.
Concepts Body Part, Organ, or Organ Component (T023)
MSH D007002
SnomedCT 37899009
English Hypoglossal Nerve, Hypoglossal Nerves, Nerve, Hypoglossal, Nerves, Hypoglossal, Cranial Nerve XII, Cranial Nerve, Twelfth, Cranial Nerves, Twelfth, Nerve XII, Cranial, Nerve, Twelfth Cranial, Nerves, Twelfth Cranial, Twelfth Cranial Nerve, Twelfth Cranial Nerves, cranial nerve XII, Nervus hypoglossus [XII], Hypoglossal nerve tree, Hypoglossal nerve [XII], cranial xii nerve, nerve xii, cranial nerve xii, Nerve XIIs, Cranial, Cranial Nerve XIIs, 12n, hypoglossal nerve, twelfth cranial nerve, Nervi hypoglossalis, Nervus hypoglossus, HYPOGLOSSAL NERVE, XII, Nerve, Nerve XII, Nervus Hypoglossus, Hypoglossus, Nervus, Nerve XIIs, XIIs, Nerve, Twelfth cranial nerve, Hypoglossal nerve, Cranial nerve XII, Hypoglossal nerve (XII), Hypoglossal nerve structure (body structure), Hypoglossal nerve structure, Hypoglossal nerve, NOS
French Nerf hypoglosse, Nerf crânien 12, Nerf grand hypoglosse, Douzième paire crânienne, Douzième nerf crânien, Nerf crânien XII
Swedish 12:e kranialnerven
Czech nervus hypoglossus, nerv podjazykový, podjazykový nerv, XII. hlavový nerv
Finnish Kielen liikehermo
Russian POD"IAZYCHNYI NERV, 12-I CHEREPNO-MOZGOVOI NERV, 12-Й ЧЕРЕПНО-МОЗГОВОЙ НЕРВ, ПОДЪЯЗЫЧНЫЙ НЕРВ
Japanese 舌下神経, 第12脳神経
German ZWÖLFTER HIRNNERV, Hirnnerv XII, Nervus hypoglossus, XII. Hirnnerv
Italian Nervo cranico XII, Dodicesimo nervo cranico, Nervo ipoglosso
Latvian Zemmēles nervs
Polish Nerw XII, Nerw podjęzykowy
Norwegian Hjernenerve 12, 12. hjernenerve, Nervus hypoglossus, Tungens bevegelsesnerve
Spanish Nervio Craneal XII, XII Par Craneal, XII par craneal, duodécimo nervio craneal, duodécimo par craneal, duodécimo par craneano, estructura del nervio hipogloso (estructura corporal), estructura del nervio hipogloso, nervio craneal XII, nervio hipogloso (XII), nervio hipogloso, Doceavo Nervio Craneal, Nervio Hipogloso, XII Nervio Craneal
Portuguese XII Par Craniano, XII Nervo Craniano, Décimo Segundo Nervo Craniano, Nervo Craniano XII, Nervo Hipoglosso
Dutch Nervus hypoglossus, XIIe hersenzenuw

Ontology: Hypoglossal nerve nucleus (C0228802)

Definition (NCI) A motor nucleus within the medulla oblongata with axons projecting to the tongue muscles.
Definition (CSP) motor nucleus for the hypoglossal nerve, supplying tongue muscles (all but the palatoglossus).
Concepts Body Part, Organ, or Organ Component (T023)
SnomedCT 280169002, 47361005
English Hypoglossal nucleus, Nucleus of hypoglossal nerve, 12, hypoglossal nerve nucleus, hypoglossal nucleus, Hypoglossal nerve nucleus, Nucleus nervi hypoglossi, Nucleus hypoglossalis, Hypoglossal nucleus (body structure), Twelfth cranial nerve nucleus, Hypoglossal nerve nucleus (body structure), Hypoglossal Nucleus, Nucleus of the Hypoglossal Nerve, nucleus hypoglossalis, nucleus nervi hypoglossi
Spanish núcleo del hipogloso (estructura corporal), núcleo del hipogloso, núcleo del XII par craneal, núcleo del duodécimo nervio craneal, núcleo del duodécimo par craneal, núcleo del duodécimo par craneano, núcleo del nervio hipogloso (estructura corporal), núcleo del nervio hipogloso