ear Flashcards
where are the organs for hearing and balance found
internal ear
organ for hearing
cochlea
organ for balance
semicircular canals
concha is made up of
cymba (upper) and cavity (lower)
EAM is a canal that leads from
auricle to tympanic membrane
what separates the EAM from middle ear
tympanic membrane
what bone attaches to the tympanic membrane
malleus
middle ear is in what part of the skull
petrous part of temporal bone
two parts of the middle ear
- tympanic cavity
- epitympanic recess
middle ear communicates with what posteriorly
mastoid area
middle ear communicates with what anteriorly
nasopharynx
*PT tube connects middle ear to nasopharynx
roof of middle ear
- epitympanic recess
- “tegmental wall”
- separates it from MCF
floor of middle ear
- “jugular wall”
- separates it from IJV
- has an opening for the tympanic n
tympanic n is a branch of what CN
glossopharyngeal (CN9)
lateral wall of middle ear
- tympanic membrane
- “membranous wall”
- chorda tympani (CN7-facial) crosses here
medial wall of middle ear
- “labyrinthine wall”
- has a prominence for facial n
tympanic plexus of nerves is found where
on the promotory of the medial wall
tympanic plexus
- begins with tympanic branch (CN9)
- also has a branch from internal carotid plexus
- lesser petrosal n leaves it
tympanic plexus of nn supplies
- mucosa of middle ear
- mastoid area
- PT tube
where does chorda tympani n enter the middle ear
posterior (mastoid) wall
chorda tympani n exits the middle ear via
anterior (carotid) wall
what does the anterior wall separate middle ear from
- PT tube
- internal carotid a and plexus
what m enters ear through anterior wall
tensor tympani m (above PT tube)
what “feeds” into the tympani plexus of nn
- tympani n (CN9) from floor
- branch from internal carotid plexus from anterior
what exits the tympani plexus
lesser petrosal n (leaves anterior wall)
PT tube connects
middle ear to nasopharynx
what connects the tympanic membrane to the oval window
ossicles
name the three ossicle bones
incus, malleus, stapes
which bone is attached to the tympanic membrane
malleus
what attached to the oval window on medial wall
stapes
tensor tympani m
- origin: PT tube, greater wing of sphenoid, petrous part of temporal bone
- insertion: malleus
- action: pulls malleus medially; tenses tympanic membrane; reduces force of vibrations
- nerve: n to medial pterygoid m (CNV3)
stapedius m
- origin: pyramidal eminence
- insertion: neck of stapes
- action: contract in response to loud noise; prevent excessive oscillations
- n to the stapedius m (facial n)
internal ear
- petrous part of temporal bone
- bony: cochlea; vestibule; semicircular canals
- membranous: utricle and saccule; ducts
organs of balance
semicircular duct, utricle, and saccule
organ of hearing
cochlear duct
-contains scala vestibuli (waves to apex) and scala tympani (waves to base)
receptor of auditory stimuli
spiral organ (organ of Corti)
special afferent fibers to the internal ear
vestibulocochlear n (CN8)
cochlear n
hearing
vestibular n
balance
nerve supply to spiral organ and cochlear duct
cochlear n (CN8)
nerve supply to semicircular ducts, utricle, and saccule
vestibular n (CN8)
