Ear Flashcards
What structures does the external ear contain?
The auricle and the external acoustic meatus
what does the auricle contain?
cartilage
what does the auricle do?
captures waves and sounds
Where does the external acoustic meatus span from and to
spans from the auricle to the tympanic membrane
what is the lateral 2/3 of the external acoustic meatus made up of?
cartilage
what is the medial 1/3 of the external acoustic meatus made up of?
temporal bone
what is the purpose of the external acoustic meatus?
to direct sound waves into the ear
what does the external acoustic meatus contain?
ceriminous glands, and debris traping hairs
what is the purpose of the tympanic membrane
to vibrate in response to incoming sound waves AND to separate the external and middle ear
where does the external acoustic meatus end?
at the tympanic membrane
What is the purpose of the middle ear
collect and amplify sound waves and to transmit sound to internal ear
what structures does the middle ear contain?
auditory ossicles, the tympanic membrane, the eustachian tube,
where does eutahcian tube span from?
middle ear to the nasal sinus cavity
what is the purpose of the eustachian tube?
to balance pressure in middle ear, to drain fluid from middle ear, to protect the ear from hearing any sounds the body causes and nasal drainage
what bones are a part of the auditory ossicles?
malleus, incus, and stapes
what is the purpose of the auditory ossicles
to connect the tympanic membrane and internal ear
what are the muscles of the middle ear?
tensor tympani and the stapedius
what do the muscles of the middle ear do?
prevent excessive vibration of the bony ossicles
what presses against oval window?
the stapes pushes against oval window to transmit sound waves to internal ear
what does the round window do?
help sounds waves travel through the internal ear
internal ear
innermost compartment of the ear, encased in temporal bone, gives sensations of hearing and balance
what is the internal ear composed of?
bony labyrinth and membranous labyrinth
what does the bony labyrinth make p?
the cochlea, the vestibule, and 3 semicircular canals
what is the purpose of the cochlea
the cochlea serves as a sensory organ for hearing that sends information to the brain
vestibule is composed of
utricle and saccule
the vesitbule detects
head position, gravity, and linear acceleration
the vestibule functions to
maintain stability and posture
the semicircular canals function to
detects rotational motion is 3 different planes and maintain balance
where are sensory hair cells located?
the cochlea
what to sensory hair cells detect
motion
what do sensory hair cells do
hearing and balance
what is in the bony labyrinth of the internal ear
perilympth
what is in the membranous labyrinth of the bony ear
endolympth
how does sound transmission work in the ear?
sounds waves are transmitted through the external ear to the tympanic membrane, vibrations pass through the ossicles of the middle ear, the stapes pushes against the oval window causing waves in perilympth of the cochlea.
Next the waves of the perilympth push against the basilar membrane as they travel through the cochlea, Hair cells will then push against the tectorial membrane - when they bend a neural signal is transmitted. Lastly, impulses travel to the CNS via cochlear branch of CN 8
the scala vestibuli is part of what structure
the cochlea
the scala tympani is part of what stucture
the cochlea
what is the cochlear duct called
the scala media
what structure is the helicotrema a part of
the cochlea
where is the organ of corti?
in the cochlea
what in the middle ear is responsible for sound detection
hair cells
in the vestubular apparatus - what does the vestibule do?
detects head position, gravity, and linear acceleration as well as maintains stability and posture
in the vestibular apparatus what do semicircular canals do?
detects rotational movement and maintains balance
what is dynamic equilibrium?
maintaing balance when head and body are moved suddenly
what is static equilbrium
maintainuhng posture and stabiltiy when body is motionless
what part of the ear is in charge of dynamic equilibrum
semicircular ducts
what part of the ear is in charge of static equilibrium
saccule and utricle
what is an ampulla?
swollen region containing sensory receptors
what are cristae ampullaris
sensory hair cells clustered on ampulla
what are the saccule and utricle of the vestibule?
membranous sacs filled with endolympth
what detects horizontal acceleration?
utricle
what detects vertical acceleration
saccule
