Cranial nerves

• Superior orbital fissure has 4 cranial nerves
• Oculomotor nerve runs through superior orbital fissure
• Trochlear nerve runs through superior orbital fissure
• The trigeminal contains 3 branches

  • Opthalmic
  • Maxillary
  • Mandibular
• Opthalmic branch of trigeminal runs in superior orbital fissure
• Abducer muscle runs through superior orbital fissure
• Maxillary branch of trigeminal runs through foramen retundum
• Mandibular branch of trigeminal nerve runs through foramen ovalis
• Internal acoustic meatus contains the facial and vestibulo-cocholear nerves
• Jugular foramen has 3 CN
• Jugular foramen runs the glosopharangeal, vagus and accessory nerves
• Hypoglossal canal has the hypoglossal nerve
• The trigeminal nerve originates from the pons
• The abducers, facial and vestibulocochlear sits on the pons- medullary junction
• The glosopharangeal, vagus, accessory and hypoglossal all sit on the medulla
• Olfactory is associated with sense of smell
• Optic is associated with vision
• Occulomotor is associated with movement of the eyeball and eyelid
• Occulomotor also has parasymapthetic function of pupil dilation
• Trochlear arises on the inferior colliculus of the midbrain
• Occulomotor nerve arises near the cerebral aqueduct
• Occulormotor nerve enters via the cavernous sinus
• Damaged occulomotor nerve can lead to ptosis (drooping eyelid)
• Trochlear nerve innervates the superior oblique muscle of eye movement
• Damage to trochear nerve can lead to eye lined upwards and head tilt
• Abducens innervates the lateral rectus muscle
• Damage to the abducens nerve can lead to eye resting in adduction (squint)
• Trigemeinal nerve is involved in face sensation and chewing
• Facial is involved in taste sensation and facial expression
• Facial is also involved in the secretion of salivia and tears
• Damage to facial nerve can lead to reduced salvation and loss of taste
• Vestibulocochlear nerve is involved in balance and hearing
• Glossopharangeal nerve is involved in posterior taste sensation, speech and swallowing
• The glossopharangeal nerve is involved in the gag reflex
• Damage to glossopharangeal nerve can be observed by no gag reflex
• Vagus nerve provides visceral sensation to heart and abdomen and swallowing
• Drugs can target to vagus nerve to slow heart rate (beta blockers)
• Damage to vagus nerve can see difficulty swallowing
• Accessory nerve is involved in shoulder shrugging
• Accessory nerve is tested by head rotation and shoulder shrugging