Week 4 - Study Guide - Hearing Flashcards
Three parts of the ear
External
Middle
Internal ear (labyrinth)
Where is the pinna (auricle)?
Ear flaps
Where is cerumen produced?
Auditory canal
What function does earwax serve?
Deters insects
waterproofing
help prevent ear infections
Where is the external acoustic meatus?
Hole through the skull
canal through the skull to middle ear and inner ear
Middle ear is for
hearing
Air and bones to amplify sound
Tympanic cavity
Tympanic Membrane
at the border between the external and middle ear
eardrum
AKA
Tympanic membrane
Middle ear is filled with
Air
an air-filled tympanic cavity
The connection between the middle and inner ear is
the Oval and Round window
Oval window is a membrane associated with
vestibular canal
where the sound wave enters
Round window is a membrane associated with
tympanic canal - an inner component
where the sound waves leave
Oval window is where
on the stapes
Round window is where
round window is below the stapes
Middle ear has a connection from the ear to throat - what is it?
3 names
1. Auditory tube
2. Pharyngotympanic (auditory) tube
3. Eustachian tube
The auditory tube is open to ?
Open to the pharynx
What is the function of the auditory tube?
to equalize pressure of middle ear and the atmosphere
Feature in the middle ear
Epitympanic recess
is the dead-end cavity
Epitympanic recess may what?
detect very low wavelength sound
Name the three auditor ossicles from lateral to medial
- Malleus = hammer
- Incus = anvil
- Stapes = stirrup
Malleus is physically associated with…
with the tympanic membrane (eardrum)
What bone is closely associated with the oval window?
Stapes
3 auditory ossicles working –
- when the tympanic membrane vibrates
- ossicles pick up the vibration
- and they MAGNIFY it 20X
How much do the ossicle bones amplify sound?
20x
Internal Ear is about
Hearing & Balance
senses Rotation of head and Linear movement of head
What is the open space within the cavity of the skull called?
Bony Labyrinth
Where do you find the structures:
Vestibule
Semicircular canals
cochlea
Bony Labyrinth
Details about the bony labyrinth:
- Membrane lined
- filled with perilymph fluid
- located in the temporal lobe
What is the hollow tube within the bony labyrinth?
Membranous Labyrinth
Inner membrane that has more fluid
What type of fluid is in the membranous labyrinth?
endolymph fluid
What two things are in the Membranous Labyrinth?
- Endolymph fluid
- Receptors
Associated with either Balance & equilibrium or Hearing
Equilibrium sensors of the inner ear…
Contain Hair cells-
- Vestibular sensors - including the utricle and saccule
- Semicircular Canals
Vestibular Sensors are really good at general awareness of…
- influenced by gravity
- head position - whether you are right side up, upside down, off at an angle
- linear accel/decel - walking, running, walking sideways, up and down an elevator
All linear positions of motion where your head is moving on a straight trajectory
Semicircular Canals are all about…
angular accel/decel
rotation of the head including acceleration and deceleration.
If your head is rotating in space- the semicircular canals will sense it
The structure within the cochlear called
the Organ of Corti
What is the function of the Organ of Corti?
It responds to vibration
- that are picked up from the tympanic membrane and the ossicles picking up the vibration from the oval window
- interpret based on the sensors that get stimulated
- And what kind of action potentials are sent to the brain
The Cochlea has three regions -
- Vestibular canal (scala vestibuli)
- Cochlear Duct (scala media)
- Tympanic canal (scala tympani)
The cochlea has two membranes
- vestibular
- basilar
helicotrema
Feature that is the dividing line between the (top region) vestibular canal (scala vestibule) (where canal narrows)
And the (bottom region) Tympanic canal (scala tympani) begins
Sound waves enter this window and exit this window
enter the oval window
exit the round window
What bone is associated with the oval window?
stapes
What is inferior to oval window?
round window
Round window connects to
round window is the membrane that connects up to the middle ear again