Cranial Nerves Flashcards
what is the name of the first cranial nerve
olfactory nerve
describe the route of the olfactory nerve
if exits the forebrain and runs through the cribriform foramen to form the olfactory bulbs
what is the function(s) of the olfactory nerve
sense smell
how can you test the olfactory nerve
using smelling salts on one nostril at a time
what can cause damage to the olfactory nerve
head damage or tumour of the frontal lobes
what is the name of the second cranial nerve
optic nerve
describe the route of the 2nd cranial nerve
exits the forebrain and goes through the orbital canal to the orbit of the eye to supply the retina
what is the function of the 2nd cranial nerve
sense sight
what is the optic chiasma
where nerve fibres from the optic nerves cross over
what does impingement on the optic chiasma by a pituitary tumour cause
bitemporal hemianopia
how do you test the 2nd cranial nerve
visual tests
pupil reflexes
looking at optic disc for papillodema
what is papillodema
where the optic disc is swollen and blurry
what causes papillodema
raised intracranial pressure
what is the 3rd cranial nerve
oculomotor nerve
what is the route of the oculomotor nerve
arises from the midbrain and goes through the cavernous sinus and through the superior orbital fissure
what is the function of the 3rd cranial nerve
supplies most of the muscles controlling eye movements
autonomic fibres control pupil constriction and lens thickness
controls muscle to keep eyelids open
how do you test the 3rd cranial nerve
look at eye movements, pupil light reflexes and drooping of eye lids
what is the first sign of compression of the 3rd cranial nerve and why does this occur first
the parasympathetic fibres are located on the outside of the nerve, so these would be compressed first causing pupil dilation
what causes compression of the 3rd cranial nerve
raised intracranial pressure forcing the uncut past the tentorium cerebelli to push on the nerve
what is the 4th cranial nerve
the trochlear nerve
what is the route of the trochlea nerve
exits the midbrain and goes through the cavernous sinus and the superior orbital fissure
what is the function of the 4th cranial nerve
supplies the muscle which moves the eye up
what is the test for the 4th cranial nerve
eye movements
what signs/symptoms may result from damage to the 4th cranial nerve
diplopia
what is the 5th cranial nerve
trigeminal nerve
what are the 3 main branches of the trigeminal nerve
ophthalmic, maxillary and mandibular
describe the route of the ophthalmic nerve branch
comes from the trigeminal at pons and goes through the cavernous sinus and the superior orbital fissure
describe the route of the maxillary nerve branch
comes from the trigeminal at pons, goes through the cavernous sinus and the foramen rotundum
describe the route of the mandibular nerve branch
comes from the trigeminal at pons, goes through foramen ovale
where does the infraorbital nerve branch from
the maximally branch of the trigeminal nerve
describe the route of the infraorbital nerve
goes through the floor of the orbit
what is the function of the infraorbital nerve
sensation to the lower eyelid and Cheek
where does the inferior alveolar nerve branch from
the mandibular branch of the trigeminal nerve
describe the route of the inferior alveolar nerve
enters the mandible at foramen mandible. goes through the bone and exits at the chin becoming the mental nerve
what is the function of the mental nerve
supply sensation to the chin, lip and lower gum
what is the functions of the trigeminal nerve
supplies muscles of mastication
sensation to the face
how can you test the trigeminal nerve
test face sensation, muscles of mastication and corneal reflex
what is trigeminal neuralgia
where you get sharp shooting pains in the face
through what nerve does shingles and corneal ulcers affect
ophthalmic
what is the 6th cranial nerve
abducens
what is the route of the 6th cranial nerve
exits pons and goes through the cavernous sinus and the superior orbital fissure
what is the function of the 6th cranial nerve
allows lateral movement of the eye
what is the 7th cranial nerve
facial nerve
what are the 5 branches of the facial nerve
temporal, zygomatic, buccal, mandibular, cervical
describe the route of the facial nerve
exits pons and goes through the internal acoustic meatus and the petrous bone. then travels through the salivary gland where it branches
what is the function of the 7th cranial nerve
supplies muscles of facial expression
supplies taste to 2/3 anterior tongue
autonomic innervation to salivary and lacrimal glands
how do you test for the 7th cranial nerve
corneal reflex
test muscles of facial expression
what is the 8th cranial nerve
vestibulocochlear nerve
what is the route of the 8th cranial nerve
comes from pons and through the internal acoustic meatus
what is the function of the 8th cranial nerve
hearing and balance
what type of tumour may impinge on the 8th cranial nerve and what other nerves may be affected
an acoustic neuroma of the Schwann cells
may also impinge on the trigeminal nerve and facial nerve giving facial tingling and motor weakness
what is prebyacusis
old age related hearing loss
what is the 9th cranial nerve
glossopharyngeal nerve
what is the route of the 9th cranial nerve
comes from the medulla and exits through the jugular foramen where it goes into the thorax
name 2 major branches of the 10th cranial nerve and what they travel beneath
left and right recurrent laryngeal nerves
right goes under subclavian artery
left goes under the aortic arch
what is the function of the glossopharyngeal nerve
sensation of soft palate, oropharynx and tonsils innervates middle ear sensory to carotid body and sinus autonomic innervation of parotid taste to lateral 1/3 of tongue sensation of tongue
what is the test for the 9th cranial nerve
gag reflex
what is the 10th cranial nerve
vagus nerve
describe the route of the 10th cranial nerve
goes from the medulla through the jugular foramen and into the thorax and gut through the carotid sheath
what is the function of the 10th cranial nerve
sensation to pharynx and larynx
muscles of soft palate, pharynx and larynx
parasympathetic innervation to gut and thorax
how do you test for the 10th cranial nerve
looking at uvula when saying “Ahh”
note speech, gouging and swallowing
what symptom is seen with damage to the laryngeal nerves
hoarse voice
what is the 11th cranial nerve
accessory nerve
describe the route of the accessory nerve
comes from the medulla and travels thoughts jugular foramen
which part of the accessory nerve goes through the posterior triangle
spinal nerve root
what is the function of the 11th cranial nerve
motor supply to trapezius and SCM
what is the test for the 11th cranial nerve
shrugging shoulders against resistance
moving head against resistance
how can the 11th cranial nerve be damaged
lymph node biopsy
stab wounds
surgery
what is the 12th cranial nerve
hypoglossal nerve
describe the route of the 12th cranial nerve
from the medulla and though the hypoglossal foramen
what is the function of the hypoglossal nerve
tongue movement
does hypoglossal nerve damage has ipsilateral or contralateral effects
ipsilateral