Test 1 Review Flashcards
Sclala tympani and scala vestibuli are filled with _______________ fluid
Perilymph
The Main Function of the auricle/pinna is to ________________
Catch sound and funnel it down to the external auditory canal.
Somas/cell body of the auditory neurons are located in the _______________
Modiolus
Ligaments and muscle attachments to the Incus:
posterior and superior ligaments
The space in the middle-ear cavity above the tympanic membrane is the_______________.
Epitympanic recess
The ______________ primary transducer of mechanical to electrochemical energy
Inner hair cells
In the United States, the # born with a detectable level of hearing loss in one or both ears.
About 2 to 3 out of every 1,000 children
a pressure increase of 44 to 1 corresponds =
increase of approximately 33 dB SPL
Which muscle connects to the manubrium of malleus?
Tensor tympani
The middle-ear muscle which contracts in order to reduce the amplitude of vibration of a sound and which is innervated by a branch of the facial nerve(VII) is the ________________.
Stapedius Muscle
Separates the scala media from the scala tympani
The Basilar Membrane
Pathology:
A disorder of hearing organs
The bottom canal/chamber of the bony labyrinth
Scala tympani
The three middle ear bones that make up the ___________ chain are the ___________, ______________ and the stapes.
Ossicular, malleus, incus.
How many “outer” hair cells do we have?
3 to 4 rows of 12,000-20,000
The stria vascularis is located in the scala media and functions to ______________
- Carry blood
- Supplies oxygen and other nutrients
- Produce endolymph.
The 2 structures of the tympanic cavity
- Tympanum (main portion)
* Epitympanic recess (attic or upper area)
Attachment 1 for the suspension of the ossicular chain system:
- Attachment of malleus to the eardrum (at umbo)
- Indudomalleolar/Malleoincudal joint
- Incudostapedial joint
- Attachment of the stapes footplate to the oval window
One purpose of the Eustachian tube is to match the pressure of the middle ear to the pressure of the __________________.
Outer ear
How many Americans aged 12 years or older have a hearing loss in both ears?
One in eight people in the United States (13% or 30 million.
The middle canal/chamber
Scala media or Cochlear Duct
Which ME muscle is innervated by cranial nerve V (trigeminal)
Tensor tympani
In the cylindrical cable of the 8th nerve, the outer portion is made up of :
Base/high frequency fibers
What percentage of the inner radial fibers innervate the inner hair cells?
90 - 95%
Neurons enter the cochlea through the
Habenula Perforata
A groove in the lateral wall
Tympanic sulcus
Ligaments and muscle attachments to the Malleus:
lateral, anterior, and superior ligaments; tensor tympani muscle
The central core around which the cochlea winds is called the __________________.
Modiolus
What attaches to the TM via the manubrium?
Malleus
The human tympanic membrane is comprised of ______________ layers.
Three
Opened by actions of these two muscles of the soft palate during the acts of swallowing, yawning, talking, etc.
- Levator palitini
2. Tensor veli palitini
The tips of the outer hair cells are imbedded in the _______________ membrane.
Tectorial
n the cylindrical cable of the 8th nerve, the inner portion is made up of :
Apical/low frequency portion
Cerumen/earwax is produced in the _______________ portion of the external ear canal.
Cartilaginous
Endolymph fluid is _____ potassium and _____ sodium)
high (potassium)
low (sodium)
The point of maximum retraction of the Tympanic Membrane is the _______________.
Umbo
Explain the Curved-Membrane Buckling Principle
–Buckling action (of the eardrum)
- Eardrum buckles as it moves due to its attachment to the manubrium of the malleus (umbo) and firm attachment to the tympanic annulus
What Contains fibrous middle layer, Makes up 2/3 to ¾ of the eardrum, Primarily responsible for sound transmission?
Pars tensa
The top canal/chamber of the bony labyrinth
Scala vestibuli
What 4 things make up the Peripheral auditory system?
• Outer ear (auricle/pinna, external auditory meatus and canal) • Middle ear • Inner Ear • VIII cranial nerve
How Are Hair Cells Stimulated?
- Movement of the basilar membrane
2. Movement of the Perilymph fluid.
A stiff cartilaginous ring at the periphery which fits into the tympanic sulcus
Tympanic annulus
The ___________ = narrower and stiffer, reacts best to higher frequencies
Base
Impairment:
An abnormal function of the auditory system
What is connected to the head of the malleus (middle
ossicle)
Incus
The contents of the Cartilaginous portion of the external ear canal.
- hair follicles
- sebaceous (sweat & oil secreting) glands
- ceruminous (wax secreting) glands
Name the 5 parts of the Inner Ear
- Vestibular portion
- Auditory portion
- Fluid filled system
- Bony labyrinth
- Membranous labyrinth
The Tympanic Membrane is considered part of the:
Middle Ear
The 8th Nerve exits the bony labyrinth via the
Internal auditory meatus.
The tympanic membrane is held in position at the end of the external auditory canal by a ring of tissue called the ___________________.
Tympanic annulus
The dB reduction of Acoustic Reflex
10-30 dB reduction
-for frequencies below 1000 Hz
The small opening allowing passage of perilymph from the scala vestibili to the scala tympani is called the ______________
Helicotrema
What percentage of the inner radial fibers innervate the outer hair cells?
5 - 10%
The fluid that surrounds the membranous labyrinth is _________________
Perilymph
Name the elements of the Vestibular Portion
- Sensory receptor cells and organs for balance
- Utricle
- Saccule
- Semicircular canals
Approximately how many Americans over 18 report some trouble with hearing?
Approximately 15% or 37.5 million
Name the 3 ossicles that make up the ossicular chain:
Malleus, Incus, and the Stapes.
E-tube opening the nasopharynx is normally kept closed by actions of two muscles
- Salpingopalatius
2. Salphingopharyngeus
how much dB gain loss does the middle ear make up for?
approximately 32.9 dB gain
The stapes footplate sits in the ______________ which is the connection/boundary between the middle and inner ears.
Oval window
Tallest stereocilia of the OHCs are attached to the undersurface of the __________________.
tectorial membrane
Three major functions of the ET:
- Equalizes air pressure
- Aeration
- Drainage
Where is the Tectorial membrane located
In the organ of Corti.
These fibers directly synapse with the nerve
Outer hair cells
The muscle connects to head of stapes
Stapedius
The auricle/pinna is most efficient in funneling _________ frequencies to the tympanic membrane.
Mid to high frequencies
The resonant frequency of the average adult external auditory canal is the with a range of ________________.
2500-3500hz
lies on top of the Scala Media
Spiral Organ of Corti
Periplymph fluid is _____ potassium and _____ sodium)
high (sodium)
The deep center point of attachment to the manubrium of the malleus
Umbo
The clear liquid in which the membranous labyrinth is situated.
Perilymph
forms the floor of the Scala Media
Basilar membrane
What is the most posterior-superior portion of the tympanic membrane?
Pars flaccida
The frequency response pattern of the sensory cells in the cochlea goes from the ____________ frequencies at the basal end to _________ frequencies at the apical end.
Highest, lowest
The middle-ear impedance matcher allows for a gain of approximately __________dB due to the area difference between the tympanic membrane and the oval window.
25 db SPL
Innervation of the tensor tympani muscle is from the__________________
Trigeminal, cranial nerve V
Muscle contractions of the Acoustic Reflex result in reduction of:
energy transmission of lower pitched/frequency sounds thought the middle ear
The diameter of the ear canal
5-9 mm in diameter
Which muscle is innervated by cranial nerve VII (facial)
Stapedius
Disability:
The adverse effect on a person’s life due to the psychosocial and psychological problems associated with auditory impairment.
How many “inner” hair cells do we have?
1 row of 3,500
The concha is ___________________.
The middle-most, bowl-shaped portion of the pinna, which opens into the external auditory canal.
How long does it take for Acoustic Reflex to kick in?
- a minimum of 10 ms
- it can take as long as 60-120ms to occur
The length of the ear canal
25-35 mm in length
The membranous labyrinth contains fluid called ____________________
endolymph
How long is the ET
35 mm in adults
What are the two muscles of the Middle ear?
- Tensor tympani
2. Stapedius
These fibers only synapse with afferent neurons
Inner hair cells
Scala media is filled with _________________
endolymph
This forms the ceiling of the Scala media
Reissner’s membrane
The facial nerve is cranial nerve number__________
VII
The opening of the External Auditory Meatus & Canal
Found within the squamous portion of the temporal bone.
The ___________ = wider and less stiff, reacts best to low frequencies
Apex
There are 2 __________ fibers for every 100 afferent fibers
Efferent
The largest surface area of the tympanic membrane is called _________________.
Pars tensa
Acoustic Reflex Involves contraction of what two muscles?
Stapedius and Tensor tympani
The pars flaccida portion of the tympanic membrane is also known as ___________________.
Shrapnell’s membrane
The Structures of the Middle Ear:
- Tympanum and epitympanic recess
- Tympanic membrane
- Ossicular chain
- Middle ear muscles and ligament
- Eustachian tube
Ligaments and muscle attachments to the Stapes:
annular ligament and stapedius muscle
What are the sensory cells for hearing
The inner and outer hair cells