Audiogram used to determine hearing loss:
20dB - 40dB mild
41 - 70 moderate
71 - 95 severe
The outer ear is a ___ for sound.
The middle ear is an ___ for sound.
The inner ear is a ___ for sound.
Which tube connects the middle ear and the nasopharynx and equalises the pressure of the ears?
What are the two openings found in the cochlea?
A pressure wave transmitted through the ___ window by the stapes causes ___ cells to depolarise.
If vibrations were to be passed straight from the air to the cochlea, 99% of it would be reflected due to the impedance of the liquid.
What structures overcome this?
What is this process called?
Auditory ossicles (malleus, incus, stapes)
Which fluid does pressure waves travel through?
What frequency of sound is hear at the cupula of the cochlea?
What frequency is heard in the modiolus (spirals)?
Which spaces are found above and below the scala media?
What fluid do they both contain?
Scala vestibuli above
Scala tympani below
Both contain perilymph
___ of the cilia by pressure waves causes ___ channels to open and the hair cells to depolarise.
What space sits between the scala vestibuli and the scala tympani?
What organ does it contain?
What fluid does it contain?
Organ of Corti
Which organ contains hair cells and is found in the scala media?
Organ of Corti
Is the endolymph high or low in sodium?
to allow action potentials to travel through it
The inner hair cells are involved in (hearing / balance).
(Repolarisation / depolarisation) occurs when stereocilia are deflected towards the longest fibres.
(Repolarisation / depolarisation) occurs when the stereocilia are deflected away from the longest fibres.
Which part of the brain processes sound?
(primary auditory cortex)
What are the vestibular end organs of the inner ear?
Anterior, lateral and posterior semicircular canals
What hair cells do the urticle and saccule contain?
When are they depolarised?
What is otoconia?
Calcium carbonate crystals found in the urticle and saccule
Help stimulate stereocilia supposedly
The otolith organs allow the brain to detect linear motion.
What directions do the
a) Horizontal motion
b) Vertical motion
At what angle are the semicircular canals oriented away from one another?
Cilia ___ or ___ depending on which way they are deflected.
The organs of balance on one side of the head are (stimulated / inhibited) when you turn towards that side.
The organs of balance on one side of the head are (stimulated / inhibited) when you turn away from that side.
What symptom does pathology of the organs of balance cause?
sensation of spinning
What is nystagmus?
Abnormal movement of eyes in people with vertigo - damage to balance centres, sensation of turning, vestibulo-ocular reflex
What is the vestibulo-ocular reflex?
Eyes remain fixed on object while you turn your head
With NO vestibular input, what symptom do you get?
feels like your eyes are jumping around in your head
Which antibiotic can cause total vestibular input loss causing oscillopsia?