Cranial Nerves Flashcards
Cranial Nerve I (function)
Olfactory: smell (olfaction)
SENSORY
Cranial Nerve II (function)
Optic: Visual activity (accuracy of sight, not interpretation of visual info)
SENSORY
Cranial Nerve III (function)
Oculomotor: extraocular eye movements; controls eyeball movements up, down, medially, laterally, and downward deviation
MOTOR
Cranial Nerve IV (function)
Trochlear: extraocular eye movements; responsible for downward and lateral eyeball movements
MOTOR
Cranial Nerve V (function)
Trigeminal:
i. Sensory: mediates sensation (pain, temperature, and discriminative touch) of the face, head, cornea of the eye, and inner oral cavity (the ophthalmic, maxillary, and mandibular regions)
ii. Motor: innervates the jaw muscles that control chewing
Cranial Nerve VI (function)
Abducens: extraocular eye movements; responsible for lateral deviation of the eyeball (looking laterally)
MOTOR
Cranial Nerve VII (function)
Facial:
i. Sensory: innervates the taste receptors on the anterior tongue
ii. Motor: innervates muscles of facial expression, muscles for eyelid closing, stapedius muscle (controls the stapes of the middle ear)
Cranial Nerve VIII (function)
Vestibulococholear:
i. Auditory Branch: transmits sensory impulses that result from the vibrations of the fluid in the cochlea; function = hearing
ii. Vestibular Branch: receives sensory stimulation from the semicircular canals of the inner ear; concerned with balance and the sensations of vertigo (dizziness); functions = balance, equilibrium, and the position of the head in space
SENSORY
Cranial Nerve IX (function)
Glossopharyngeal:
i. Sensory: taste on posterior aspect of the tongue
ii. Motor: swallowing
Cranial Nerve X (function)
Vagus:
i. Visceral Branches (carries both sensory and motor info): Sensory carries taste info from the palate and epiglottis; Motor carries parasympathetic info to and from the heart, pulmonary system, esophagus, and GI tract
ii. Skeletal Muscle Branches (carry motor info): Carries motor info to the muscles of the larynx, pharynx, and upper esophagus (muscles responsible for swallowing and speaking)
BOTH
Cranial Nerve XI (function)
Accessory: Controls elevation of the larynx during swallowing; Innervation of SCM muscle allows: Head Rotation to contralateral side, Head flexion/extension;
Innervation of the upper trapezius muscle allows for: Shoulder elevation & shoulder flexion above 90 degrees
MOTOR
Cranial Nerve XII (function)
Hypoglossal: innervates the muscle of the tongue (responsible for tongue movement)
MOTOR
CN I (clinical signs)
-Loss of Smell
CN II (clinical signs)
- Abnormal Pupil Size
- Loss of Vision
- seeing rainbows/Halos
- visual field loss
CN III (clinical signs)
- Outward & Down ward Rotation of the Eye
- Double Vision
- Dilated Pupil
CN IV (clinical signs)
- Weakness with downward eye movements
- Double Vision
- limited convergence
CN V (clinical signs)
- Stabbing, Shooting, Shocking, or Burning in the Face: cheek, jaw, teeth, gums, lips, eyes, forehead
- weakness and wasting of jaw muscles
- jaw deviates towards involved side (mandibular branch)
- asymmetric chewing (if damage is unilateral)
- impaired cutaneous and proprioceptive sensation from face and mouth
- no blink reflex when cornea is touched (ophthalmic branch)
CN VI (clinical signs)
- Double Vision
- Affected Eye pulled toward the Midline
- Tilting/Rotating of Head
CN VII (clinical signs)
- Difficulty keeping food/drink in mouth
- concerns with making sounds that require lip movement
- reduction in muscle tone in the face
- paralysis or paresis of ipsilateral muscles of facial expression
- can’t taste
CN VIII (clinical signs)
- Hearing Loss
- Vertigo
- False Sense of Motion
CN IX (clinical signs)
- Concerns with gag/swallow reflex (afferent)
- Impairment of Taste
- Parotid Gland Dysfunction
- sensation absent at neck
- senses carotid BP
CN X (clinical signs)
- Difficulty Speaking
- Loss of Voice
- Difficulty Drinking
- Abnormal HR and/or BP (senses aortic)
- Concerns with gag and swallow reflex (efferent)
CN XI (clinical signs)
- Shoulder Pain
- Winging of Shoulder Blades
- swallowing concerns
CN XII (clinical signs)
- Weakness of the Tongue
- Difficulty Speaking
- tongue deviated to side of damage (if unilateral)
