Lecture 22: Hearing Flashcards
What is the stimulus of hearing?
sound
What is sound?
high and low pressure waves in the air
What happens as the sound loudness increases?
you can damage your ear
What are the three sections of the ear called?
outer, inner and middle ear
What three structures make up the outer ear?
the pinna, the external auditory canal and the tympanic membrane
What is another name for the tympanic membrane
the ear drum
Where is the pinna and what is its purpose?
It is the outside of the ear and as the sound waves come into the ear, the pinna reflect the sound waves down the external auditory canal
Where is the external auditory canal located?
it travels to the tympanic membrane
What section of the ear is behind the tympanic membrane?
the middle ear
Is the middle ear fluid filled or air filled?
air filled
How is the air maintained in the middle ear?
by the auditory (eustachian) tube
What happens when there is an increase in pressure in the middle ear?
it puts pressure on the tympanic membrane and causes it to bow out (painful)
How can we relieve the pain from the increase in pressure in the middle ear?
this is done by the auditory (eustachian tube) because it goes down to the back of the nose (nasopharynx) to get air from the atmosphere into the middle ear cavity
When we hear the squeal/pop of our ears, what is happening?
this is the pressure equalising - the air is escaping down the eustachian tube and being replaced
When can the eustachian tube be blocked?
during a cold
What are the bones in the middle ear called?
malleus
incus
stapes
What is the collective name for the bones in the middle ear?
the ossicles
What is the role of the ossicles?
to transfer vibrations from sound waves from the tympanic membrane to the inner ear
Describe what happens to the sound waves that enter the ear
they come down the external auditory canal and cause vibrations of the tympanic membrane and this is transferred to the malleus which moves which causes the incus to move and this causes the stapes to move and this delivers the vibrations into the inner ear
What are the 3 components of the inner ear?
- the semicircular canal
- the cochlea
- the vestibulocochlear nerve
What is the semicircular canal for?
balance
Describe the cochlea
it is fluid filled tubes
Is the inner ear filled with fluid or air?
fluid
What are the 3 components of the external ear?
- pinna
- external auditory canal
- tympanic membrane
What are the 2 components of the middle ear?
- ossicles
- eustachian tube
How many chambers of the cochlea are there?
3
What are the three names of the chambers of the cochlea in order from top to bottom?
Scala vestibuli
Scala media
Scala tympani