Transcript WARM UP 4/24

WARM UP 4/24
What does each do?
1.
Medulla
2.
Olfactory cell
3.
Cones
4.
Temporal lobe
5.
Pituitary gland
6.
Vestibulocochlear nerve
7.
Taste bud
8.
Hypoglossal nerve
9.
Retina
NOTES CH 11 4/24
The ear
AUDIOLOGY
The study of the ear
The ear consists of 3 parts:
1.
2.
3.
Outer
Middle
Inner
OUTER EAR
PINNA – part you see
 EXTERNAL AUDITORY CANAL
 CERUMINOUS GLANDS – produce wax
to protect the ear
 TYMPANIC MEMBRANE (eardrum)

MIDDLE EAR
EUSTACHIAN TUBE –
links the ear to the
throat. Purpose is to
equalize pressure in the
ear.
 Normally flat – unequal
pressure, EX: yawning
or high altitudes – opens
up and hear a “popping”
sound


Tube more
horizontal when
younger –
reason to never
give baby bottle
on back.
Milk can go into
the ears and
cause infection/
earache
OTITIS MEDIA –
ear infection.
3 SMALLEST BONES
HAMMER, ANVIL, STIRRUP
(malleus, incus, stapes)
These transmit vibration of the eardrum to the
inner ear

INNER EAR

COCHLEA – snail like area filled with fluid
where auditory cells and hairs are located

SEMICIRCULAR CANALS – 3 tubes
where fluid located; helps with equilibrium
EQUILIBRIUM
1.
2.
STATIC – detect up and down movement of
head. (Tiny calcium stones in fluid hitting
against hairs when move)
DYNAMIC – detects angles and whole body
movement (Fluid moves in semicir canals)
Both messages are sent to the cerebellum
Why still feel movement when
stop?
The fluid is still moving in the ears and
sending message to brain that you are still
moving.
Why nausea? Eyes give message not moving,
ears give message you are – conflict in the
brain
Constant sound or constant movement (like in
a car) – your body adapts and soon ignores
it so you don’t notice it any more
DEAFNESS
1. CONDUCTION – vibration being stopped
2. SENSORINEURAL – damage to receptor
cells (hairs), nerve or temporal lobe of
brain
Facts About Hearing Loss
•More than 40 million Americans have hearing
loss.
•Approximately 40% of the hearing-impaired are
under age 65.
•About 2 million children under age 18 are
hearing-impaired in the U.S.
•Minor decreases in hearing, especially of higher
frequencies, are normal after age 20.
•Some form of hearing loss affects 1 out of 5
people by age 55.
•Hearing loss is the third leading chronic disability,
following arthritis and high blood pressure.
•Between 7 and 10 million people in American
industry have noise-induced hearing loss,
virtually all of which was preventable.
•About 15% of college graduates have a level of
hearing loss equal to or greater than their
parents; a significant cause is listening to loud
music.
•In the U.S., 12 million people have hearing
aids.
EAR LABELING
1.
2.
3.
4.
5.
6.
7.
Pinna
External auditory
canal
Tympanic membrane
Stirrup
Eustachian tube
SKIP
cochlea
8.
9.
10.
11.
Vestibulocochlear
nerve
Semicircular canal
Anvil
Hammer
HEARING PHYSIOLOGY
1.
2.
3.
4.
5.
6.
7.
Sound
Through auditory canal
Tympanic membrane vibrates
Hits hammer
Hits anvil
Hits stirrup
Presses on outside of cochlea
8.
9.
8.
9.
Fluid moves
Hairs bend (action potential starts)
(# of cells stimulated determines
loudness)
Message through vestibulocochlear nerve
Brain interprets at the temporal lobe of
cerebrum