Cranial Nerves Flashcards
What nerves do not originate from the brain stem
CN I olfactory
CN II optic
CN XI accessory
what is the nemonic for remembering the sensory or motor or both for the cranial n
some say marry money but my brother says big brains matter most
what is the nerve function for CN I olfactory
special sensory smell
Where do CN I olfactory nerve cell bodies arise from
olfactory epithelium in the nasal cavity
what are the deficits for the olfactory nerve
anosmia- loss of smell
what is the olfactory nerve bony passage
cribriform plate in the ethmoid bone
what function does the optic n have
special sensory sight
what is the optic chiasm
sella turcica of sphenoid bone
nerves cross over
what is the optic tract
nerves stay on lateral side for the optic n
location of optic nerve cell bodies
retinal ganglia
what are the optic n deficits
visual defects
what bony passage does the optic n pass through
optic canal
what artery supplies the optic n
ophthalmic a
what muscles attach to the sclera
extraocular muscles- superior rectus, inferior oblique, middle rectus, lateral rectus, inferior rectus, superior oblique
LR6
lateral rectus
CN VI abducens- abducts eye
SO4
superior oblique
CN IV trochlear- down and out
AO3
all other muscles CN III oculomotor superior rectus- up/in inferior oblique- up/out inferior rectus- down/in medial rectus- adducts
what is the function of oculomotor n
M: SR, IR, IO, MR and levator palpebrae superioris
PS: pupil constriction (sphincter pupillae) and lens accommodation (ciliary- near vision)
where is the location for oculomotor nerve cell bodies
midbrain
what are the deficits of the oculomotor n
ptosis- superior eyelid drop caused by paralysis of levator palpebrae superioris
lateral strabismus- eye directed down and out
absent pupillary light reflex
dilated pupil
lack of lens accommodation
what bony passage does oculomotor pass through
superior orbital fissure
what is the function of the trochlear n
superior oblique- down and out
where is the location of trochlear nerve
posterior midbrain
** only CN to exit posterior surface of brainstem
what are the deficits of the trochlear n
superior oblique weakness
diplopia- double vision when looking down
what bony passage does trochlear n pass through
superior orbital fissure
what is the function of the trigeminal nerves
M: mastification
S: skin sensation of forehead, maxilla, mandible
what are the branches and functions of the trigeminal n
V1- ophthalmic- sensory
V2- maxillary- sensory
V3- mandibular- sensory and motor
what are the mastification muscles
temporalis
masseter
medial pterygoid
lateral pterygoid
what are some of the sensations for the trigeminal n
face eye sinuses nasopharynx anterior 2/3 tongue ear
what is the location of trigeminal nerve cell bodies
trigeminal ganglion- s
pons
what are the deficits for the trigeminal n
weakened mastication muscles
loss of facial sensation
loss of cornea reflex- sensation
what are the bony passages for the trigeminal branches
V1- superior orbital fissure
V2- foramen rotundum
V3- foramen ovale
what is the function for the abducens n
lateral rectus- abduct eye
what is the location for the abducens nerve cell bodies
pons
what are the deficits of the abducens n
loss of ability to move eye laterally
medial strabismus
what is the bony passage the abducens n pass through
pierces dura covering the clivus then enters superior orbital fissure
what is the function for the facial n
M: facial expression
S: taste sensation ant. 2/3 tongue
PS: salvia production of sublingual and submandibular glands, tear production from lacrimal gland, mucous glands of nasal cavity, maxillary sinus, palate
what is the location of the facial nerves cell bodies
M: pons
S: geniculate ganglion
what is the facial n deficits
loss of corneal reflex- motor
weakened facial expression
loss of taste ant. 2/3 tongue
what bony passage does the facial n pass through
internal acoustic meatus
what is the function of the vestibulocochlear n
hearing and balance
special sensory
what is the location of the vestibulocochlear nerve cell bodies
vestibular ganglion
spiral ganglion
what are the deficits of the vestibulocochlear n
tinnitus- ringing or buzzing in ear
vertigo- dizziness, loss of balance
loss of hearing
what is the bony passage the vestibulocochlear n pass through
internal acoustic meatus
what is the function of glossopharyngeal n
M: swallowing
S: taste sensation post. 1/3 tongue, palantine tonsil, oropharynx, middle ear, carotid body and sinus
PS: salvia production of parotid gland
what is the location of the glossopharyngeal nerve cell bodies
M: medulla
S: sensory ganglion
what are the deficits of the glossopharyngeal n
loss of taste on post. 1/3 tongue
changes in swallowing
absent gag reflex (ipsilateral)
palate deviation (contralateral)
what is the bony passage the glossopharyngeal n pass through
jugular foramen
what is the motor function for vagus n
swallowing speech cardiac plexus pulmonary plexus esophageal plexus foregut and midgut larynx pharynx soft palate
what is the shared function of the vagus n
sensory and motor to thoracic and abdomen
what is the sensory function of the vagus n
larynx and laryngopharynx
taste from epiglottis and pharynx
what cranial nerves have parasympathetic fibers
CN 3,7,9,10
where is the location of the vagus nerve cell bodies
M: medulla
S: superior and inferior ganglion
what the deficits of the vagus n
dysphagia- difficulty swallowing anesthesia of larynx weak/hoarse voice dysphonia- difficulty speaking aphonia- no speaking HR abnormalities
what is the bony passage for the vagus n
jugular foramen
what is the function of the accessory n
sternocleidomastiod- head RT and cervical flexion
trapezius- shoulder shrug
where is the location of the accessory nerve cell bodies
rootlets from the upper 5-6 segments of cervical spinal cord, through foramen magnum and into jugular foramen
what are the deficits to the accessory n
weakness of the muscles
what is the function of the hypoglossal n
major tongue muscles
where is the location of hypoglossal nerve cell bodies
rootlets of anterior medulla
what are the deficits of the hypoglossal n
tongue deviates toward damaged nerve (ipsilateral)
what bony passage the hypoglossal n pass through
hypoglossal canal
name the cranial n
CN I- olfactory CN II- optic CN III- oculomotor CN IV- trochlear CN V- trigeminal V1- ophthalmic, V2- maxillary, V3- mandibular CN VI- abducens CN VII- facial CN VIII- Vestibulocochlear CN IX- glossopharyngeal CN X- Vagus CN XI- acessory CN XII- hypoglossal
where do you find CN I on the brain
occipital lobe
where do you find CN II on the brain
superior to the midbrain
where do you find CN III on the brain
between midbrain and pons
where do find CN IV on the brain
laterally between the cerebrum and pons
where is CN V located on the brain
lateral part of pons
where is CN VI on the brain
between the pons and medulla
where is CN VII on the brain
lateral the CN VI between the pons and medulla
where is CN VIII on the brain
lateral to CN VII at the junction of the pons and medulla
where is CN IX on the brain
lateral to the medulla
where is CN X on the brain
group of rootlets from lateral surface of the medulla
where is CN XII on the brain
ascending through foramen magnum, lateral to the medulla
where is CN XII on the brain
aterolateral medulla
