Neurology Book


Cold Exposure

Cranial Nerve 5

Aka: Cranial Nerve 5, Cranial Nerve V, Trigeminal Nerve, CN 5
  1. See Also
    1. Trigeminal Neuralgia
  2. Physiology: General
    1. Largest Cranial Nerve
    2. Sensory root innervates head and face
    3. Motor root innervates mastication muscles
  3. Physiology: Course
    1. Fibers originate in 2 nuclei
      1. Nucleus in Pons
      2. Substantia gelatinosa
    2. Course from pons to trigeminal ganglion at petrous apex
  4. Physiology: 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
  5. 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

Trigeminal nerve structure (C0040996)

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
English Cranial nerve V, Fifth Cranial Nerve, Fifth Cranial Nerves, Nervus Trigeminus, Trigeminal Nerve, Trigeminal nerve structure, Trigeminal nerve tree, Trigeminal Nerves
Spanish estructura del nervio trigemino, nervio craneal V, nervio trigemino, quinto nervio craneal, quinto par craneal, quinto par craneano, V par craneal
Parent Concepts Cranial Nerves (C0010268), Peripheral Nervous System (C0206417), root (of UWDA hierarchy) (C0391807)
Derived from the NIH UMLS (Unified Medical Language System)

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