Cranial Nerves Flashcards
CN I
Olfactory nerve
- Smell (sensory)
- Receptors in roof of nasal cavity
- Leads into olfactory tract => 1° olfactory cortex (temporal lobe)
Damages: Hyposomia (reduced smell), Anosmia (loss of smell)
CN II
Optic nerve
- Vision (sensory)
- Receptors in retina
- Visual fields projected onto visual cortex are inverted/reversed
Damage: defects in visual field
CN III
Oculomotor nerve
- Somatic motor + parasympathetic (mixed)
- Moves extra-ocular muscles (eyeball in orbit) + pupillary constriction + accommodation
Damage: pupillary dilation, ophthalmoplegia (weakened/paralyzed eye mvts)
CN IV
Trochlear nerve
- Supplies super oblique muscle (motor)
- Rare to have isolated damage
CN VI
Abducent nerve
- Supplies lateral rectus muscle (abducts eye; motor)
- Vulnerable to injury from head trauma/raised intracranial pressure
Damage: Strabismus (paralysis of LR), Diplopia (double vision)
CN V
Trigeminal nerve
1) Ophthalmic - eyeball + forehead (sensory)
2) Maxillary - cheek, teeth, nasal (sensory)
3) Mandibular - mandible (sensory + motor)
Damage: Tic Douloureux (Trigeminal neralgia)
CN VII
Facial nerve
- Facial expressions (motor) + taste in anterior 2/3 tongue (sensory)
Damage: Bell’s Palsy (hemi-facial paralysis); Loss of taste / ability to salivate / lacrimination in one eye
CN VIII
Vestibulocochlear nerve (sensory)
1) Vestibular - balance + equilibrium
Damage: Meniere’s syndrome (vertigo, nausea, vomit)
2) Cochlear - hearing
Damage: deafness
CN IX
Glossopharyngeal nerve
- Supplies tongue + pharynx (mixed)
- Regulates gag reflex
Damage: Difficulty in swallowing; no gag reflex
CN X
Vagus nerve (mixed)
Damage: difficulty in speech, swallowing
CN XI
Spinal Accessory nerve (motor)
1) Cranial supplies palate, pharynx, larynx
2) Spinal supplies trapezius, SCM
Damage: Weakness in shrugging shoulders + turning head against resistance
CN XII
Hypoglossal nerve
- Supplies tongue muscles (motor)
Damage: Inability to protrude tongue symmetrically
