II. Anatomy

  1. Central CN 5
    1. neuroCn5central.png
  2. Facial Distribution
    1. neuroCn5V123.jpg
  3. Trigeminal Nerve
    1. neuroTrigeminalNerveGrayBB778.gifLewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
  4. Alveolar Nerve (V3)
    1. entAlveolarNerveGrayBB779.gifLewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)

III. Physiology: General

  1. Largest Cranial Nerve
  2. Sensory root innervates head and face
  3. Motor Root innervates mastication Muscles
  4. Fibers cross the midline in the Brainstem (at the level of the motor or sensory nucleii)
    1. Cortical or thalamic CVA involving the trigeminal signals
      1. Affects the contralateral face
    2. Brainstem CVA involving the trigeminal signals
      1. Injures the trigeminal nucleii or crossing fibers, affecting the ipsilateral face
      2. May injure the Trigeminal Lemniscus affecting the contralateral face

IV. Anatomy

  1. Trigeminal Lemniscus
    1. Fibers from the Trigeminal nucleii cross the midline and combine to form the Trigeminal Lemniscus
    2. Trigeminal Lemniscus courses up to the contralateral Thalamus
    3. Signals are ultimately transmitted to the contralateral cerebral cortex
  2. Nucleii (fibers originate in two nuclei)
    1. Motor Nucleus
      1. Small and localized to the Pons
    2. Sensory Nucleus
      1. Very long nucleus (extends from Midbrain to spinal cord)
      2. Mesencephalic nucleus of CN 5 (proprioception) is most superior, in the Midbrain
      3. Main sensory nucleus of CN 5 (light touch) is within the pons
      4. Spinal nucleus of CN 5 (pain and Temperature sense) is in the lower Medulla and upper spinal cord
  3. Course
    1. Course from pons to trigeminal Ganglion at petrous apex

V. Anatomy: Innervation (Divides into three branches)

  1. Ophthalmic Branch (Sensory)
    1. Cornea
    2. Ciliary body
    3. Conjunctiva
    4. Nasal cavity
    5. Sinuses
    6. Skin of eyebrows, forehead, and nose
  2. Maxillary Branch (Sensory)
    1. Side of nose
    2. Lower Eyelid
    3. Upper lip
  3. Mandibular Branch (Sensory and Motor)
    1. Sensory
      1. Temporal
      2. Auricular
      3. Lower face
      4. Lower lip,
      5. Oral Mucosa
        1. Anterior two thirds of Tongue
        2. Mandibular gums and teeth
    2. Motor (Mastication Muscles):
      1. Masseter Muscle
      2. Temporalis Muscle
      3. Pterygoid Muscle

VI. Exam

  1. Motor
    1. Normal
      1. No Tremor, Involuntary chewing, or Trismus
      2. Symmetrically, and tightly clenches teeth
    2. Paralysis
      1. On mouth opening, Mandible deviates to weak side
      2. Vertical misalignment of central medial incisors
  2. Sensory
    1. Oral Mucosa
    2. Jaw
    3. Cheek
    4. Forehead
  3. Reflexes
    1. Jaw Jerk Reflex
      1. Tests both sensory and motor Trigeminal Nerve
    2. Corneal Reflex (Cornea touched with cotton whisp)
      1. Tests both Sensory CN 5 and Motor CN 7
      2. Consensual reflex results in bilateral blinking

VII. Associated Conditions

VIII. 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

Neuro Atlas (FPnotebook.com) Open in New Window

Images: Related links to external sites (from Bing)

Related Studies

Ontology: Trigeminal nerve structure (C0040996)

Definition (NCI_CDISC) The fifth set of paired nerves of the face that emerge from the brain steam. These nerves have sensory and motor functions in the face, oral cavity, and nasal cavity. (NCI)
Definition (NCI) The fifth set of paired nerves of the face that emerge from the brain steam. These nerves have sensory and motor functions in the face, oral cavity, and nasal cavity.
Definition (NCI_NCI-GLOSS) The main sensory nerve of the head and face, and the motor nerve of the muscles used in chewing.
Definition (MSH) The 5th and largest cranial nerve. The trigeminal nerve is a mixed motor and sensory nerve. The larger sensory part forms the ophthalmic, mandibular, and maxillary nerves which carry afferents sensitive to external or internal stimuli from the skin, muscles, and joints of the face and mouth and from the teeth. Most of these fibers originate from cells of the TRIGEMINAL GANGLION and project to the TRIGEMINAL NUCLEUS of the brain stem. The smaller motor part arises from the brain stem trigeminal motor nucleus and innervates the muscles of mastication.
Definition (CSP) fifth and largest cranial nerve, a mixed motor and sensory nerve; the larger sensory part forms the ophthalmic, mandibular and maxillary nerves, and the smaller motor part inervates the muscles of mastication.
Concepts Body Part, Organ, or Organ Component (T023)
MSH D014276
SnomedCT 27612005
English Nerve, Trigeminal, Nerves, Trigeminal, Trigeminal Nerve, Trigeminal Nerves, Cranial Nerve V, Cranial Nerve, Fifth, Cranial Nerves, Fifth, Fifth Cranial Nerve, Fifth Cranial Nerves, Nerve V, Cranial, Nerve, Fifth Cranial, Nerves, Fifth Cranial, V, Cranial Nerve, cranial nerve V, Trigeminal nerve tree, Trigeminal nerve [V], Nervus trigeminus [V], cranial nerve v, trigeminal nerves, nerve trigeminal, nerve v, nervus trigeminus, v nerve, 5n, trigeminal nerve, fifth cranial nerve, Nervus trigeminus, NERVE, TRIGEMINAL, TRIGEMINAL NERVE, Trigeminus, Nervus, Nerve Vs, Nervus Trigeminus, Nerve V, Fifth cranial nerve, Trigeminal nerve, Cranial nerve V, Trigeminal nerve structure (body structure), Trigeminal nerve structure, Fifth cranial nerve, NOS, Trigeminal nerve, NOS
French Nerf crânien V, Cinquième nerf crânien, Cinquième paire crânienne, Nerf crânien 5, Nerf trijumeau
Swedish Trigeminusnerv
Czech nervus trigeminus, trojklanný nerv (nespr.), trojklaný nerv, V. kraniální nerv, V. hlavový nerv
Finnish Kolmoishermo
Japanese 三叉神経, 第5脳神経
German FÜNFTER HIRNNERV, Hirnnerv V, Nervus trigeminus, V. Hirnnerv
Italian Quinto nervo cranico, Nervo cranico V, Nervo trigemino
Latvian Trijzaru nervs, Trīszaru nervs
Polish Nerw V, Nerw trójdzielny
Norwegian Nervus trigeminus, Trillingnerve, 5. hjernenerve, Hjernenerve 5
Spanish V Par Craneal, Nervio Craneal V, V par craneal, estructura del nervio trigémino (estructura corporal), estructura del nervio trigémino, nervio craneal V, nervio trigémino, quinto nervio craneal, quinto par craneal, quinto par craneano, Nervio Trigémino, Quinto Nervio Craneal, V Nervio Craneal
Portuguese V Par Craniano, V Nervo Craniano, Nervo Craniano V, Nervo Trigêmeo, Quinto Nervo Craniano
Dutch 5e hersenzenuw, Nervus trigeminus, Ve hersenzenuw

Ontology: trigeminal lemniscus (C2327327)

Concepts Body Part, Organ, or Organ Component (T023)
English Trigeminothalamic tract, Trigeminal lemniscus, trigeminal lemniscus-1, trigeminal tract, trigeminal lemniscus, trigeminothalamic tract, dorsal and ventral trigeminothalamic tracts, trigeminothalamic tract-1, quintothalamic tract, central trigeminal tract, Tractus trigeminothalamicus, Lemniscus trigeminalis