Week of 4/10? Flashcards
Draw a picture of the Pharyngeal structures (including pharynx, laryngopharynx, pharyngoconstrictor x3, lat pharyngeal wall [and its gaps], and stylopharyngeus)
Which set of tonsils are the ones we see [when doing oropharyngeal exam)? Which ones can we not see?
We See Palatine
Can’t see the Tubal tonsils
What important oriface is blocked by the tubal tonsils? What function does the orifice have?
Pharyngotympanic tube orifice
Important for equalizing ear pressure!
If these tubal tonsils swell –>blocks the orifice –> get increased pressure and PAIN
Are there lingual tonsils?
?maybe? check notes.
What is the blind ending of the laryngopharynx called? Where does it sit?
The piriform recess?
SIts in front of the neurovascular bundle
Where does the superior pharyngoconstrictor (SPC)?
pharyngobasilar fascia
Wheres does the mid pharyngoconstrictor (MPC) attach? What does it overlap?
attaches to hyoid
overlaps the SPC
Wheres does the Inf pharyngoconstrictor attach (IPC)? What does it overlap?
it attaches to thyroid
Overlaps the MPC
What CN (cranial nerve) innervates all of the PC’s (sup, mid, inf)? Now be specific
CN X
-pharyngeal branch of CN X
-recurrent laryngeal branch of CN X?
-ext laryngeal branch of CN X?
How do the PC’s contract? (what kind of pattern)
Sequentially!
(almost like peristalsis)
What are the purpose of the lateral pharnygeal wall gaps?
How many gaps are there?
allow structure
4 gaps
What are the important structures/things in the LPW gap 1?
levator palatini
auditory tube
ascending palatine Artery
What are the important structures/things in the LPW gap 2?
stylopharyngeus
CN IX
stylohyoid ligament
What are the important structures/things in the LPW gap 3?
Internal laryngeal Nerve
Superior laryngeal Artery & Vein
What are the important structures/things in the LPW gap 4?
Recurrent laryngeal nerve
Inf Laryngeal Artery
What is unique about the innervation of the stylopharyngeus?
Its the only internal pharyngeal muscle that is innervated by CN IX
Where does the CN IX arise from (whihc arch)
4th pharyngeal arch
What are all the other internal pharyngeal muscles innervated by?
Which one is the exception to this?
CN X
The exception: stylopharyngeus is CN IX
What vessel brings blood to all the pharyngeal muscles/structures?
What drains them?
External carotid
drained by the inferior aveolar vein
What nerve provides motor function for the pharyngeal structures?
-exception 1?
-exception 2?
All motor supply is from CN X EXCEPT:
1) tensor veli palatini gets it from CN V
2) stylopharyngeus is from CN IX
What nerve supplies sensory function to pharyngeal muscles?
except?
Sensory is IX
except for the inferior laryngopharynx, which gets sensory from CN X
Where do the sympathetic fibers of the pharyngeal muscles come from?
the superior cervical ganglion
What lymph node(s) drain the pharyngeal structures?
Deep cervical LN’s
EXCEPT: the tonsils are drained by the jugulodigastric LN
What are people with allergic rhinitis 3x more likely to develop then the [regular] population?
Asthma
What is medicamentosa?
A harry potter spell
JK! It’s ppl who use nasal decongestants and essentially get addicted to them
What is the physiology of medicamentosa?
Decongestants decrease venous plexus [vasoconstrict it?] –>when the drug wears off, you get rebound congestion
How long is it okay to use nasal decongestants?
3 days before damage begins to occur
How do you treat medicamentosa? 2 ways?
Weaning process; can take 17-41 days
OR
Surgery
What histoloigic changes do nasal decongestants cause?
-obstinate vasodilation
-inflammation edema
-cilia loss
-goblet cell hyperplasia
What CN is responsible for smell?
Anatomically how does it do so?
CN 1!!!
-it has 50 fascicles (tiny branches?) that go through the cribiform plate
WHat is the important gland involved in our sense of smell? How does it work?
Bowmans Gland
-it dissolves odorant to bind [to cribiform plate?] and to wash away the odorant
What is Naegleria fowleri? aka N fowleri
WHo/where would be most likely to get N fowleri?
An Amoeba!!
-accesses nasal cavities through cribiform plate & eat neurons in the brain causing PAM (Primary Amebic Meningoencephalitis)
-95% deadly
-most commonly affects males (dumb & dunk heads in water) in the south (ameoba likes warm water)
terror moment: you can get it from tap water or neti pots as well
What is the histology of the Tonsilar RIng?
crypts w/ respiratory epithelium = [up arrow] up location = pharyngeal tonsil
What is the histology of the palatine tonsils? (different then most?)
stratified squamous epithelium
What type of muscle makes up the oropharynx?
skeletal muscle
What is the histology of the epiglottis?
stratified squamous & elastic cartilage
What is the histology of the true vocal cords?
stratified squamous and NO glands
False vocal cord histology?
skeletal muscle, resp epithelium AND goblet cells
(opposite of what you would think because they are actually superior to true vocal cords, and thus farther away from trachea and resp organs that have similar histo)
What nerve is used for balance & orientation?
Which CN is it part of?
Vestibular Nerve
Which is part of CN 8 (vestibulocochlear nerve)
Tell me what happens at each stage of ear embryologic development:
-week 4?
-week 6?
-week 7?
-week 8?
-week 4: otic placode forms
-week 6: cochlear duct forms
-week 7: spiral organ of corti forms (which turns mechanical signals into nerve signals)
-week 8: get full 2.5 circles of inner ear/cochlea
What is the ductus reunions?
connection btw saccule and cochlear duct
what do the outer and inner ridges of the cochlear duct form, respectively?
outer ridge forms hair cells
inner makes the tectorial membrane
What is sensorineural deafness?
abnormal hair cells or abnormal auditory nerve conduction
What conditions are associated with sensorineural deafness?
herpes
drugs
down syndrome
prematurity
What pharyngeal arches are involved in forming the inner ear including canal?
what does each arch form specifically & which CN is associated with each arch?
the 1st and 2nd pharyngeal arches
1st: middle ear, auditory tube, malleus, incus, tendor Tympanion –> (CN V)
2nd: stapes & stapedius muscle –> CN VII
What embryologic [sub]structure forms all the ossicles?
neural crest
What is the histology of mastoid air cells and what are their significance?
endoderm epithelium dissolves bone to make sinuses
What happens if there is no meatal plug regression during inner ear formation?
congenital deafness
What do external ear malformations indicate? (embryologically what happened to cause this)
neural crest defects
Conductive hearing loss, what is it?
something that stops sounds from getting through the outer or middle ear. This type of hearing loss can often be treated with medicine or surgery.
What are some causes of conductive hearing loss? or some conditions related to it
COnditions:
-ankylosis (fixed stapes)
-treacher collins
-down syndrome
Other causes:
-foreign object
-ruptured ear drum
-ear wax build up
-allergies
-fluid etc
What type of hearing loss do ppl with downs syndrome have?
Trick question! They can have either/both sensorineural or conductive hearing loss
Discuss the Lesser Petrosal Nerve
-which CN is it part of?
-what types of fibers does it carry? and to where?
-continuation of CN IX
-carries preganglionic parasympathetic
-carries them to the otic ganglion & parotid gland
maybe related to GVEP (can’t tell, see notes)
What does the chorda tympany SVA do?
responsible for taste to anterior 2/3 of tongue
What does chorda tympany GVE-P do?
carries parasympathetic to submandibular and sublingual salivary glands
What odd symptom/deficit can be a consequence of ear surgery?
bonus if you can tell me why
you can have loss of taste
Probably due to injury [of the chorda tympany SVA] as its transmitted through the petrotympanic fissure
WHat can chronic otitis media lead to?
inflammation of the jaw bone, aka mastoiditis
What is the internal ears major organ?
vestibulocochlear organ
What CN is related to the vestibulocochlear organ
CN VIII (vestibulocochlear nerve)
what do the utricle and saccule of inner ear do?
proprioception; vertical and horizontal orientation
What are the three scala of the vestibulocochlear organ
scala vesitbuli (top)
scala media (middle)
scala tympani (bottom)
What is Meneires disease/what causes it?
defective endolymph flow or absorption
Symptoms/signs:
-one sided?
-vertigo
-hearing loss
-tinnitus
-aural fullness/congestion
Which parts of the kinetic labyrinth are involved in movement perception and which direction of movement?
ampula & crista
deal with rotational movement
What parts of the linear labyrinth are involved in movement perception and how?
otoliths (sensory apparatus is maculae?)
feel acceleration
Describe how rotation is is perceived
rotation is registered on contralateral side in the opposite canal
ex: head turn to L = cupula on L moves anterior and R moves posterior
Describe the cilia on hair cells and how they are involved in perceiving movement in the inner ear?
All hair cells have top linked stereocilia & kinocilium
Kinocilium are aligned in the same direction
-when you move in one direction it causes hyperpolarization in one canal, and depolarization in the opposite
What are the main vestibular functions of CN VIII and where are those parts of CN VIII that do each function (name 3)
1) eye movements compensate for head movement
-done by efferents of CN8 that control EOM
2) adjust posture to head position
-cerebellar and spinal cord portions of cn VIII
3) mediate awareness of movement
-the portion of CN 8 that runs from thalamus to cortex
What element/electrolyte is unique in endolypmh?
It has higher K+, which leads to K+ influx into cells
Name the major sound organ (think easy)
COchlea!!
What separates the scala?
osseus spiral lamina
What is reissners membrane?
separates endolymph and perilymph
Where is the organ of corti [attached]? What is it made up of?
Attached to the basilar membrane
It is 3000 fibers!! different lengths hear different frequencies
What fibers of the organ of corti hear low frequency and where are they located?
Long fibers hear low frequency and are at the apex of the OoC
What fibers of the organ of corti hear high frequency and where are they located?
short fibers hear high frequency and are at the base of OoC
Why do hair cells need a bath?
Bath of perilymph
if they didn’t get this the neurons wouldn’t work right due to high K+ in endolympph (so gotta wash this away, just as memory aid to remember)
inner hair cells do what?
auditory transduction
outer hair cells do what?
fine tuning
After K+ in the endolymph has been driven into cells, what happens next? WHat Neurotransmitter is released [usually]?
Ca+ influx happens with depolarization –> glutamate (NT) –> goes to vestibular Nerve
What is VOR? What triggers it and how does the signal travel/where?
Horizontal head move triggers VOR –> ascending medial long fasciculus (MLF) –> bilateral CN motor center –> EOM
(note, this can also be triggered by some vertical movements as well)
What is Nystagmus
slow VOR motion that then jerks back other direction quickly
The nystagmus is named for the quick jerk direction
COWS…
What is it? and give examples
Cold Opposite, Warm Same
SO cold water in R ear, eyes track R, then jerk left
Warm in R ear, eyes track left then jerk right
Where are the otoliths? What do they do?
Otoliths are in statoconic membrane, when they move they displace hair cells
saccular otoliths –> vertical
utricle –> horizontal
what is otoconia
calcium carbonate cryystal
What is the vestibulocolic reflex?
Where is it primarily located?
Reflex responsible for stabilizing head as it moves and coordinates EOM with it
located in MVST (descending MLF) –> bilateral innervations –> cervical area targets
What is the vestibulospinal reflex?
Where does it primarily lie/located?
Controls body posture
LVST –> ipsilateral innervation –> to cerebellar partner
Where does the vestibulocerebellar tract run/synapse? Tricky, 2 parts
vestibular cerebellar tract –> one path to synapse in vestibular nucleus
–> 2nd path skips that nucleus and goes straight to scarpas ganglion
How does alcohol trigger vertigo?
which way will your nystagmus go if you are drunk vs sobering up?
Etoh changes enodlymph density
Drunk nystagmus: R beating
Sobering up: L beating
What causes BPPV? what is the mechanism of bppv
detached otoliths move into semicircular canals
can be from aging or trauma (that detaches otoliths)
HOw do we treat BPPV
Movements: to get the otolith to come out of semi circular canals (like dix hallpike maneuver and others)
Otherwise the otolith will dissolve on its own
What artery would be involved in an ischemic stroke that causes problems with the VOR, VCR, and/or VSR?
PICA thrombus
You have an ischemic stroke that causes problems with the VOR, VCR, and/or VSR
describe each lesion/deficit or what you will see
VOR –> resting nystagmus will be opposite of lesion (left jerk = R sided lesion [in PICA])
VCR –> head tilts toward the lesion
VSR –> fall toward the side with the lesion
sensory trigeminal damage: where is it located? what does it cause?
damage to ipsilateral noci
disrupts thermosense
You have a lesion/stroke that causes contralateral loss of pain & temperature in trunk and limbs? Where did the lesion/injury occur/affect?
spinothalamic
What happens if the nucleus ambiguous sustains damage/injury?
Depends on location:
1)injury to spympathetic pathway –> horners syndrome (ptois and anhydrosis on which side?
2)injury to spinocerebellar disruption –> ipsilateral ataxia
What is ROmberg sign? where has there been an injury?
Closed eyes and swaying, or even falling
vestibulocerrebellar injury
