EAR

what is the pinna aka the auricle primarily composed of?

elastic cartilage except the lobule contains fibroadipose

what does the external auditory meatus aka the auditory canal do

conducts sound to the tympanic membrane

what is a myringotomy

incision of the eardrum to relive pressure of drain middle ear

what is a myringopalsty

eardrum repair

where is the cone of light of the tympanic membrane located

anterior-inferior-it is a reflection of the otoscope light

what is the innervation of the external ear

lesser occipital, greater auricular, facial, auriculotemporal, vagus

what is the ear cough reflex

arnold reflex, stimulation of the external acoustic meatus elicits a couch , auricular branch of vagus—>thats why cough

what is Ramsay hunt syndrome

from herpes zoster oticum, causes hemofacial palsy, from latent VZV in the geniculate ganglion, more severe than Bells palsy

what is referred otalgia

irritation of nerves can refer pain to the ear

what are examples of referred otalgia

tonsillitis and pharyngitis—>middle ear pain—>tympanic branch of glossopharyngeal

laryngeal cancer or GERD—>ear canal pain—>auricular branch of vagus

what is the middle ear

tympanic cavity and its contents

what are the nerves of the middle ear

chorda tympani from CN VII and tympanic plexus of nerves from CN IX

what is the malleus

contains tensor tympani m, during loud noise, pulls tympanic membrane inward and tenses it, muffles transfer vibration

what is the stapes

contains stapedius m, pulls footplate into oval window, decreasing movement

what innervates malleus

trigeminal nerve

what innervates stapes

facial nerve

what is otosclerosis

stapes becomes adherent to oval window through causing conductive hearing loss, in active otosclerosis you see flamingo flush which is hyperemia of the promontory

what is the function of the pharyngotympanic tube?

to equalize pressure in the tympanic cavity with atmospheric pressure

what are the muscles of the pharyngotympanic tube

levator veli palatine and tensor veli palatine which elevates the palate and could lead to popping sound

what clinical term is associated with something wrong w pressure in pharyngotympanic tube

facial baroparesis

what is the basic mechanism of hearing in the cochlea

stapes vibrates oval window—>perilymph moves toward round window—>pressure increases and moves hair cells—>action potential and signal to brain via cochlear nerve

what is the vestibular apparatus

for equilibrium

what is the saccule

vertical position sense, contains macula sacculi

what is the utricle

for horizontal position sense, contains macula utriculi

what are the semicircular ducts in the inner ear for

detect rotational movement, filled with endolymph, each duct has an ampulla with cirsta ampullaris with hair cells

what are otoliths

calcium carbonate protein granules that add weight and inertia and enhance the sense of gravity and motion in the gelatinous otolithic membrane

what is benign paroxysmal vertigo

otoliths in the utricle are displaced and become canaliths in the semicircular canals, causes a false sense of rotation