RUSVM Physio Neuro Part 7 Audition Flashcards
How many ears is required for hearing?
atleast 1 ear
How many ears is required for localization of sound
requires 2 ears
T/F sounds are pressure waves in the air with given frequencies and amplitudes
TRUE
How is frequency of sounds perceived
as pitch
How is amplitude of sounds perceived
as loudness
The amplitude (intensity) of a sound in quantified in
Decibels (dB)
How loud can a dog bark
as loud as 108 dB
The frequency of a sound is the number of pressure oscillation cycles per unit time- how is this expressed in units
HERTZ (Hz)
Dogs can efficiently detect sounds between what Hz
30-35.000 Hz
What part of the ears does hearing involve
the external ear, middle ear and inner ear.
Where is the sensory receptor located in the ear
In the inner ear
What does the external ear do for hearing?
The external ear directs the sound waves into the ear canal.
What is the external ear composed of?
the fleshly part- Pinna and the ear canal (L shaped)
T/F the external ear is separated from the middle ear
TRUE
How is the external ear separated from the middle ear
By the tympanic membrane or eardrum.
T/F The middle ear is an air-filled cavity in the temporal bone
TRUE
How is the middle ear connected to the nasoparynx
It is connected to the nasopharynx by the auditory tube
What is the auditory tube called
the eustachian tube
What does the middle ear contain
it contains the OSSICLES and 2 small skeletal muscles.
What are the 3 tiny bones connected to each other in the Ossicle called
- Malleus
- Incus
- Stapes
Where does the Malleus connect to
connected to the ear drum
Where is the Incus
The incus is the middle ear that is between the malleus and stapes
What is the stapes connected to
the stapes is connected to the oval window
T/F The ossicles transfer vibration of the ear drum to the oval window.
TRUE
T/F the ossicles increase the amplitude of sound waves protecting the sensitive sensory cells
False - it will decrease the amplitude of sound waves protecting the sensitive sensory cells.
What does the inner ear (labyrinth) contain
it contains the sensory organs for both the auditory system and vestibular system.
What does the vestibular system detect
It detects acceleration and static tilt of the head.
What is the auditory portion of the inner ear complex called
It is called the Cochlea.
What organ does the inner ear contain
it contains the organ of CORTI which has hair cell receptors
The sensory hair cells are what type of receptors
They are mechanoreceptors.
T/F The sterocilia is able to regenerate and will not cause hearing loss.
False- the sterocilia does NOT regenerate and CAN cause hearing loss.
What membrane overlies the sensory cells
The TECTORIAL MEMBRANE
What membrane is the floor of the organ of Corti
The BASILAR MEMBRANE
What does the vibration of the organ of Corti cause
it causes bending of cilia on the hair cells by shearing force as the cilia push against the tectorial membrane
What does the bending of the cilia produce a change in
in K+ conductance of the hair cell membrane
What does the bending in one direction cause
It causes a DEPOLARIZATION - triggers K+ INFLUX
Leads to Ca channel opening and release of NT Glutamate.
What type of NT does Glutamate function as?
It functions as an excitatory NT
What does Glutamate cause
It causes and AP in the afferent cochlear nerves.
What does bending in the other direction cause
It causes a HYPERPOLARIZATION- triggers K+ EFFLUX
Glutamate is NOT released an AP is NOT Formed
What does a hyperpolarization trigger
it triggers K+ EFFLUX -> Glutamate is NOT released and an AP is NOT formed.
What is the oscilatory pattern called
Cochlear Microphonic Potential
T/F Different auditory hair cells are activated by different frequencies.
TRUE
Hair cells located at the base of the basilar membrane (inner cells) respond best to what
Best to HIGH FREQUENCIES
Hair cells located at the apex (outer cells) respond best to what
Best to LOW FREQENCIES
The basilar membrane act as what
a sound frequency analyzer
Spatial mapping of frequencies generates what
a TONOTOPIC MAP
What does the tonotopic map tell
tells where sounds of different frequency are processed in the brain
In the ascending pathway where is information transmitted from
Transmitted from the hair cells to the cochlear nerve.
