ear anatomy Flashcards
what is the auricle
The pinna, also called the auricle, is made up of cartilage that gives our ears their various shapes and sizes, and it also has a fleshy bit at the bottom- called the ear lobe, or lobule.
what does the pinna do
The pinna directs sound waves towards the opening of the ear canal.
what is the external acoustic meatus and what does it do
The ear canal, or the external acoustic meatus, is a short, curved tube that burrows through the temporal bone for about 1 inch - or 2 and a half centimeters - and ends at the tympanic membrane.
what is cerumen and what does it do
sticky, yellow-ish, earwax.
Cerumen helps prevents foreign objects or tiny insects from getting in and damaging the tympanic membrane.
what secretes ear wax
the ear canal is covered by skin, along with hair follicles and ceruminous glands - which secrete cerumen
what is the correct term for the ear-drum?
The tympanic membrane is also called the eardrum,
what cavities does the tympanic membrane divide
the external ear from the middle ear
what is the function of the tympanic membrane
When sound waves reach the eardrum, it vibrates and transmits those vibrations to the tiny bones in the middle ear.
what is the middle ear
an air-filled cavity inside the temporal bone, shaped like tiny chamber with 4 walls, a floor and a roof.
what forms the lateral wall of the middle ear
eardrum/tympanic membrane
what holes are in the medial wall of the middle ear
The internal wall has two windows: an oval window above, and a round window below.
what cavities does the medial wall of the middle ear separate?
separates the middle ear from the inner ear.
where is the mastoid antrum and what does it do
The posterior wall of the middle ear has an opening called the mastoid antrum, and it connects the middle ear with the mastoid cavity within the temporal bone.
what is the Eustachian tube?
also called the nasopharyngeal tube - tube from middle ear to nasopharynx
what are the 3 fx of nasopharyngeal tube?
-equalizing pressure across the tympanic membrane
-protecting the middle ear from reflux of fluids going up from the nasopharynx,
-clearing out middle ear secretions.
what is the roof of the middle ear called?
tegmen tympani
what is the roof of the middle ear called?
tegmen tympani/tegmental wall/
epitympanic recess is a dome shaped cavity above the ossicles
what forms the floor of the middle ear?
the floor of the middle ear is a thin layer of bone that sits right above our friendly basement neighbor - the jugular vein.
how is sound transmitted through the middle ear?
“handle” of the malleus rests on the eardrum
when the eardrum vibrates, the vibrations are transmitted from the malleus to the incus, then to the stapes, and finally to the oval window, which transfers the vibrations over to the inner ear.
what fluid fills the bony labyrinth
perilymph
what fluid fills the membranous labyrinth
endolymph
what is the inner ear also called?
labyrinth
what is responsible for hearing
cochlea
which part of inner ear is responsible for balance seeing
semicircular canals x3
what sense(s) do the movement of perilymph and endolymph contribute to?
hearing and balance
Where is the membranous labyrinth
inside the bony labyrinth
What is the vestibule?
like a hallway that leads up to two other parts or rooms - the cochlea, towards the front of our head, that deals with hearing, and a second room containing the three semicircular canals, towards the back, which play a role in balance.
what and where is the Scala vestibuli?
in the inner ear, the cochlea is like a snails shell… if you look at in cross section, the Scala vestibuli is the top
connected to the middle ear through the oval window, and contains perilymph.
what is the Scala tympani?
in the inner ear, the cochlea is like a snails shell… if you look at in cross section the Scala tympani is the bottom
connected to the middle ear through the round window, and it also contains perilymph.
what is the organ of Corti also called?
The organ of hearing, called the spiral organ, or the organ of Corti, is fixed to the basilar membrane and contains hair cells. The tips of these hair cells insert into the tectorial membrane,
what is the tectorial membrane
tectorial membrane,
a gelatinous membrane that overlies the spiral organ.
in the inner ear, what is responsible for transducing sound waves into signal we can interpret?
The organ of Corti is the mastermind of our hearing sense, and it contains our hearing receptors, or hair cells.
summarise how sound enters ear and is received
sound vibrations travel through external ear to ossicles in middle ear
malleus>incus>stapes
stapes against oval window transmits vibrations to perilymph (scala vestibuli) which transmits to the organ of Corti (in cochlear duct)
Hearing receptors convert vibrations into an electrical impulse.
1)to brain via CN8
2)perilymph (in scala tympani) is also set in motion - round window bulge back towards middle ear, relieving pressure.
which nerve takes auditory signal to brain
CN8
What angle are the semi circular canals from each other?
90degrees - three planes of motion
What two senses is the ear responsible for
hearing and balance
Name three components of vestibular. apparatus
semicircular canals
utricle and saccule
names of the three semi-circular canals?
anterior
posterior
lateral
what is inside bony semi-circular canal and where do they open into?
inside each one is a membranous semicircular duct - which contains endolymph, and opens in the utricle.
where is the macula?
what does it do
the utricle and the saccule have a region called the macula, which contain sensory cells called balance receptors.
what part of the semi circular canal detects changes in balance? how?
Inside the ampulla, there are balance receptors - also called hair cells.
Balance receptors detect changes in static equilibrium - changes in our head position in relation to horizontal or vertical acceleration because the endolymph moves in the canals
The two skeletal muscles attached to the ossicles that help dampen loud sounds are the tensor tympani and………?
stapedius
The glands in the external acoustic meatus secrete _____, which traps foreign bodies.
cerumen
The membranous labyrinth of the inner ear contains the potassium rich fluid (endolymph/perilymph) .
endolymph
The sound waves that vibrate the tympanic membrane are converted to _____ energy in the ossicles of the middle ear.
mechanical
The floor of the cochlear duct consists of the fibrous _____which supports the organ of Corti.
basilar membrane
The external portion of the cochlear duct is lined by the stria _____ a vascular mucosa that secretes endolymph.
vascularis
The external portion of the cochlear duct is lined by the stria _____ a vascular mucosa that secretes endolymph.
vascularis
The ossicles of the middle ear transmit the vibration of the tympanic membrane to the______ window.
oval
The boundary between the external and
middle ear
is the_____ membrane.
tympanic
The movement of the _____window creates fluid waves that excite the
hearing
receptors.
The movement of the oval window creates fluid waves that excite the
hearing
receptors.
The __________ is the canal that allows the
middle ear
to communicate with the mastoid air cells in the mastoid process.
The mastoid antrum is the canal that allows the
middle ear
to communicate with the mastoid air cells in the mastoid process.
The __________ is the canal that allows the
middle ear
to communicate with the mastoid air cells in the mastoid process.
The mastoid antrum is the canal that allows the
middle ear
to communicate with the mastoid air cells in the mastoid process.
The pressure measured by the force per unit area is (greater/lesser) at the oval window than at the
tympanic membrane
in order to overcome the inertia of the cochlear fluid.
The pressure measured by the force per unit area is greater at the oval window than at the
tympanic membrane
in order to overcome the inertia of the cochlear fluid.
_The
organ of Corti
is housed in the membranous
_______
.
The
organ of Corti
is housed in the membranous
cochlear duct
.
The middle ear
is located in the ______ portion of the _______
bone
.
The
middle ear
is located in the petrous portion of the temporal
bone
.
The roof of the
_______ duct
is the vestibular membrane, which separates the
scala media
from the
scala vestibuli
.
The roof of the
cochlear duct
is the vestibular membrane, which separates the
scala media
from the
scala vestibuli
.
The roof of the
cochlear duct
is the _______membrane, which separates the
scala media
from the
scala vestibuli
.
The roof of the
cochlear duct
is the vestibular membrane, which separates the
scala media
from the
scala vestibuli
.
The roof of the
cochlear duct
is the vestibular membrane, which separates the
scala _______
from the
scala vestibuli
.
The roof of the
cochlear duct
is the vestibular membrane, which separates the
scala media
from the
scala vestibuli
.
The roof of the
cochlear duct
is the vestibular membrane, which separates the
scala _______
from the
scala vestibuli
.
The roof of the
cochlear duct
is the vestibular membrane, which separates the
scala media
from the
scala vestibuli
.
The roof of the
cochlear duct
is the vestibular membrane, which separates the
scala media
from the
scala _______
.
The roof of the
cochlear duct
is the vestibular membrane, which separates the
scala media
from the
scala vestibuli
.
The bony labyrinth of the
inner ear contains (endolymph/perilymph) which is similar in composition to
cerebrospinal fluid
.
The bony labyrinth of the
inner ear contains perilymph, which is similar in composition to
cerebrospinal fluid
.
The first part of the
external acoustic meatus is elastic cartilage while the rest is carved out of the ______
bone
.
The first part of the
external acoustic meatus
is elastic cartilage while the rest is carved out of the temporal
bone
.
The scala vestibuli lies (superior/inferior) to the cochlear duct so is adjacent the oval window.
The scala vestibuli
lies superior to the
cochlear duct so is adjacent the oval window.
The mucosa that lines the
middle ear is (continuous/ discontinuous) continuous with the mucosa of the
nasopharynx
.
The mucosa that lines the
middle ear is continuous with the mucosa of the
nasopharynx
.
The middle ear is (air/fluid) filled.
The middle ear is air filled.
Swallowing or yawning briefly (opens/closes) the pharyngotympanic tube to equalize pressures between the
middle ear and
nasopharynx
.
Swallowing or yawning briefly opens the pharyngotympanic tube to equalize pressures between the
middle ear
and
nasopharynx
.
The auricle of the ear is composed of ____
cartilage covered by thin
skin
.
The auricle of the ear is composed of elastic
cartilage covered by thin
skin
.
.
The basilar membrane is (most/least) stiff at the base to detect high frequency sounds.
The basilar membrane is most stiff at the base to detect high frequency sounds.
The stapedius skeletal muscle in the middle ear attaches to the ______
The stapedius skeletal muscle in the middle ear attaches to the stapes
.
The ______ skeletal muscle in the middle ear attaches to the stapes
.
The stapedius skeletal muscle in the middle ear attaches to the stapes
.
The basilar membrane is (most/least) stiff at the apex to detect low frequency sounds.
The basilar membrane is least stiff at the apex to detect low frequency sounds.
The scala tympani is (superior/inferior) to the cochlear duct making it adjacent to the round window.
The scala tympani is inferior to the cochlear duct making it adjacent to the round window.
The scala tympani is (superior/inferior) to the cochlear duct making it adjacent to the _____ window.
The scala tympani is inferior to the cochlear duct making it adjacent to the round window.
The bony labyrinth of the
inner ear is continuous, coming to an apex at the _______
The bony labyrinth of the
inner ear is continuous, coming to an apex at the helicotrema.
The tensor tympani of the
middle ear originates from the pharyngotympanic tube and inserts on the
________
The tensor tympani of the
middle ear originates from the pharyngotympanic tube and inserts on the
malleus
The _________ of the
middle ear originates from the pharyngotympanic tube and inserts on the
malleus
The tensor tympani of the
middle ear originates from the pharyngotympanic tube and inserts on the
malleus
The tensor tympani of the
middle ear originates from the ________ tube and inserts on the
malleus
The tensor tympani of the
middle ear originates from the pharyngotympanic tube and inserts on the
malleus
The anterior wall of the
middle ear has an opening for the
_______ that connects to the nasopharynx
The anterior wall of the
middle ear has an opening for the
Eustachian (pharyngotympanic)
tube that connects to the nasopharynx
The scala media is part of the membranous labyrinth which is filled with _______
The scala media is part of the membranous labyrinth which is filled with endolymph.
The inner ear is (air/fluid) filled.
The inner ear is fluid filled.
the round window is found at the base of the cochlea and is covered by the ___________
the round window is found at the base of the cochlea and is covered by the secondary tympanic membrane.
The bony labyrinth, is within the _________
The bony labyrinth, is within the otic capsule
The membranous labyrinth is organized into the _____ and ____ within the vestibule
The membranous labyrinth is organized into the utricle and saccule within the vestibule
SCC - the ampulla contains an area of _____ epithelium called the ________, this is lined with tiny hair cells
SCC - the ampulla contains an area of sensory epithelium called the ampullary crest, this is lined with tiny hair cells
The hair cells of the ampullary crest are innervated by the ________ branch of the ________ nerve, and the cell bodies of these neurons are found in the _______ ganglion.
The hair cells of the ampullary crest are innervated by the vestibular branch of the vestibulocochlear nerve, and the cell bodies of these neurons are found in the vestibular ganglion.
The hair cells in the utricle detect movements in the _______ plane; while those in the saccule detect movement in the _____ plane
The hair cells in the utricle detect movements in the horizontal plane; while those in the saccule detect movement in the vertical plane
The utricle and the saccule both contain areas of sensory epithelium called ______, which contain hair cells that detect information about_____acceleration
The utricle and the saccule both contain areas of sensory epithelium called maculae, which contain hair cells that detect information about linear acceleration
The macular hair cells are also innervated by the _______ branch of the _________ nerve. (CN____)
The macular hair cells are also innervated by the vestibular branch of the vestibulocochlear nerve, CN8
Cochlear duct:
roof is formed by the ______ membrane, floor is formed by the ______ membrane.
Cochlear duct:
roof is formed by the vestibular membrane, floor is formed by the basilar membrane.
The ______ duct is between the scala vestibuli and the scala tympani
The cochlear duct is between the scala vestibuli and the scala tympani
The ________ (CNVII) nerve then travels through the ________, where it is accompanied by the ________ nerve and the ________ artery.
The vestibulocochlear nerve then travels through the internal acoustic meatus, where it is accompanied by the facial nerve and the labyrinthine artery.
