Cranial Nerves Pt 1 Flashcards
describe cranial neves
cranial extension of spinal nerves
12 numbered pairs, rostral to caudal (most cranial to foramen magnum)
roots located in base of brain and brainstem
pass through cranial foramina to their destination
are all cranial nerves the same
NOOO
mixed
do not all carry same info
can be sensor - visceral/somatic and motor - visceral/somatic
name types of cranial nerves
General somatic - aff/eff
general visceral aff/eff (ans)
special somatic - aff outside body
special visceral - aff inside body
give ex of general somatic cn
aff/eff
skeletal muscles in head, neck and skin
give ex of general vsiceral cn
aff/eff - ans
blood vessels
Salivary glands
intraocular muscles (control pupil dilation)
give ex of special somatic cn
aff - outside body
vision and hearing/balance
give ex of special visceral cn
aff- inside body
taste and smell
name special senses
vision
hearing/balance
taste
smell
Mnemonic for cn names
Oh = olfactory
Oh = optic
Oh = oculomotor
To = trochlear
Touch = trigeminal
And = abducens
Feel = facial
A = vestibulocochlear
Girl’s = glossopharyngeal
Very = vagus
Soft = spinal accessory
Hands = hypoglossal
Mnemonic for cn info (it carries)
Some = sensory (special)
Say = sensory (special)
Marry = motor
Money = motor
But = both
My = motor
Brother = both
Says = sensory (special)
Big = both
Brains = both
Matter = motor
More = motor
what is cn1
olfactory nerve
visceral
afferent
special sensory
odorant stimuli to brain
describe cn 1
receptor nerve endings line nasal mucosa of ethmoid (lateral and medial aspect)
fibers pass through cribriform foramina in olfactory bulb in cribriform plate =
synapse here and then onto brain via olfactory tract
fibers pass through only one direction
soft tissue - mucosa covers usually
describe cn v
trigeminal
3 roots, tripartite, big roots in pons
mixed = carries mainly sensory info from anterior head, face and jaws & motor innervation to muscles of mastication
where do all branches of cn v pass through
foramina in sphenoid
name the 3 branches of cn v
v1 = ophthalmic
v2 = maxillary
v3 = mandibular
describe cn v1 - gen
passes through orbit
Innervates forehead - sensory
describe cn v1 - sensory innervation to where
to orbit and anterior nasal = nasocilliary
anterior scalp = frontal
lacrimal gland/upper eye lid = lacrimal
describe cn v1 - exit
via superior orbital fissure
along with cn iii, iv, vi
name 3 branches of cn v1
nasociliary
frontal
lacrimal
describe nasociliary nerve - cn v1
orbit, eye (cornea), nose and nasal cavity
innervates = disappears into nasal cavity & medial wall of orbit
small nerve
describe frontal nerve - cn v1
to scalp/upper face
exits via supraorbital foramen
describe lacrimal nerve - cn v1
related to lacrimal gland (tear)= sits laterally and superiorly in own orbit
sensory for lacrimal gland
innervates surface of eye and eyelid
NOT MOTOR - wont stimulate tears
describe cn v2 - gen
passes through orbit floor and exits onto face
sensory - mouth
describe cn v2 - sensory innervation to where
cheeks, lateral nose, lower eyelids and upper lip = infraorbital
Inferior/posterior nasal cavity = nasopalatine
palate = nasopalatine, greater and lesser palatine
maxillary teeth = superior alveolar, via maxillary sinus
describe cn v2 - exit
foramen rotundum
name cn v2 branches
infraorbital
superior alveolar
nasopalatine
greater/lesser palatine nerves
describe infraorbital nerve - cn v2
in floor of orbit - maxilla
exits via infraorbital foramen
sensory innervation to side of face and nose and upper lip (skin)
describe superior alveolar nerve - cn v2
branching pattern of maxillary
sends branches to upper teeth
describe nasopalatine nerve - cn v2
lower half of nasal cavity and gums (inferior)
describe greater/lesser palatines nerve - cn v2
enter hard palate
roof of mouth and back portion of soft palate
describe cn v3 - gen
towards mandible
sensor and motor (motor to muscles of mastication)
describe cn v3 - sensory innervation to where
temple, lower face (ears, lower jaw and lip), inner cheek, anterior 2/3 of tongue = lingual, general sensation
mandibular teeth = inferior alveolar
chin = mental
describe cn v3 - exit
foramen ovale
name cn v3 branches
motor
lingual
inferior alveolar
mental
describe motor nerve - cn v3
muscles of mastication - outside
lateral pterygoid - inside and outside tempralis and masseter
describe lingual nerve - cn v3
tongue
general sensory - hot/cold, textures to anterior 2/3 of tongue
describe inferior alveolar nerve - cn v3
within mandible with branches to lower teeth
conveyed back to brain
sensory input lower teeth
exits onto face = sensory for chin/lower lip = mental foramen
describe mental nerve - cn v3
from inferior alveolar nerve
exits through mental foramen in mandible
describe cn vii - gen
facial nerve
special sensory to anterior 2/3 of tongue
taste, chorda tympani joining lingual nerve (hitchhikes)
describe cn vii - functions
motor innervation to muscles of facial expression –> somatic motor efferent
Parasympathetic to lacrimal, nasal, palatal glands and salivary glands = stimulates tear glands, mucous (hitchhikes on lacrimal)
SUBLINGUAL and SUBMANDIBULAR
where does cn vii originate
between pons and medulla = pontomedullary junction
how does cn vii exit
facial nerve comes out internal acoustic meatus (just below petrous ridge) along with cn viii –> branches to nasal, lacrimal and palatal glands, passes in wall of middle ear
leaves skull via stylomastoid foramen (free portion of cn vii to muscles of facial expression)
describe chorda tympani - cn vii
comes back into middle ear then goes out and joins lingual = special sensory (visceral), taste to ant 2/3 of tongue
describe cn ix - gen
glossopharyngeal
tongue pharynx
describe cn ix - functions
special visceral (taste) & somatic sensory to posterior 1/3 of tongue (area not covered by facial nerve)
Parasympathetic to parotid gland (sits in front of ear)- salivation
sensory/motor innervation to areas/muscles of pharynx = sends food down tube, cough if go down wrong way, gag reflex
GVA innervation to carotid body = gva from carotid body located in carotid sinus (swelling at bifurcation of internal and external carotid arteries)
describe cn ix - origin
just next to cn vii and cn viii
ponto medullary junction
describe cn ix - exit
via jugular foramen
(with cn x, xi and internal jugular vein)
what is carotid body
collection of chemoreceptors (specialized cells) at bifurcation of carotid arteries in neck (in carotid sinus)
monitors blood chemistry = ph, oxygen, carbon dioxide levels and temp
describe cn x - gen
very long
wanderer
vagus
describe cn x - functions
somatic motor to pharynx and larynx –> speech via superior and recurrent laryngeal nerves
somatic sensory to larynx
Parasympathetic to lungs, tb tree, esophagus and most guts = almost all the way to end of gut (small and 2/3rd large intestines), efferent ans
describe cn x - exit
Jugular foramen
describe cn x - root
root big
posterior to pontomedullary junction
describe cn x - secondary functions
somatic motor innervation = muscle at back of throat, continue movement of food to eso
Recurrent laryngeal = control over muscles to speak - superior and recurrent controls laryngeal muscles
describe parasympathetic innervations - gen
ans = effernt
rest and digest
craniosacral outflow
describe parasympathetic innervations - cn iii
oculomotor nerve to pupil
pupillary constriction
describe parasympathetic innervations - cn vii
facial nerve to lacrimal gland, nasal cavity, sublingual and submandibular salivary glands, palate = production of tears, saliva
describe parasympathetic innervations - cn ix
glossopharyngeal to parotid gland = increased salivation
describe parasympathetic innervations - cn x
vagus to lungs, tb tree, heart, esophagus, guts (foregut and midgut)
describe cn xi - gen
spinal accessory
motor cranial nerve only
primarily spinal organ ~C1-C6
describe cn xi - enter
foramen magnum
describe cn xi - exit
jugular foramen - onto sternocleidomastoid and trapezius muscles
describe cn xi - specifics about origin
large portion comes from spinal nerves but still considered a cranial nerve
spinal origin has to go back into cranial cavity via foramen magnum
joins cranial part and comes back out via jugular foramen and goes into muscles (sternocleidomastoid and traps)
describe cn xii - gen
hypoglossal
motor only
describe cn xii - originates
originates in medulla oblongata
passes through hypoglossal canal into neck then innervates all but one intrinsic/extrinsic tongue muscle
describe cn xii - exit
hypoglossal canal in occipital
just above foramen magnum
(ventral, inferior to vagus nerve)
describe cn xii - secondary fucntions
speech = muscles of mastication to open and close mouth
vagus modulates voice box position
move tongue around so will not touch teeth/roof of mouth
describe overlapping territories of some cranial nerves
some functions, organs or regions supplied by multiple cranial nerves
clinically useful for diagnosing lesions
describe overlapping territories of face
general somatic sensory = cn v, 3 branches trigeminal
general somatic motor = cn vii facial
describe overlapping territories of tongue
cn v3 (mandibular) = gen somatic sensory ant 2/3 of tongue (pain, texture, etc)
cn vii (facial, chorda tympani hitchhike) = special visceral sensory ant 2/3 tongue (taste)
cn ix (glossopharyngeal) = special visceral and somatic sensory to post 1/3 tongue (hot/cold from back of tongue)
cn xii (hypoglossal) = somatic motor = tongue muscles
describe overlapping territories of salivation
cn vii = glossopharyngeal (parotid)
cn ix = facial (sublingual and submandibular)
