2. 4 symtomps
Vertigo- a sensation of spinning while
stationary. It is commonly associated
with vomiting or nausea, unsteadiness
, and excessive perspiration.
Recurrent episodes in those with
vertigo are common and they
frequently impair the quality of life.
3. Tinnitus- a ringing, swishing, or other
type of noise that seems to originate in
the ear or head. It is caused by
damage to the microscopic endings of
the hearing nerve in the inner ear.
4. hearing loss- may fluctuate, especially
early on in the course of the disease.
The patient may also be especially
sensitive to loud sounds.
Eventually, most people experience
some degree of long-term hearing loss
feeling of fullness or congestion in the
ear.
5. Attacks of dizziness may come on
suddenly or after a short period of
tinnitus or muffled hearing.
Some people will have single attacks
of dizziness separated by long periods
of time.
7. The ear has external, middle, and inner portions. The outer
ear is called the pinna and is made of ridged cartilage
covered by skin. Sound funnels through the pinna into the
external auditory canal, a short tube that ends at the eardrum
(tympanic membrane).
Sound causes the eardrum and its tiny attached bones in the
middle portion of the ear to vibrate, and the vibrations are
conducted to the nearby cochlea. The spiral-shaped cochlea
is part of the inner ear; it transforms sound into nerve
impulses that travel to the brain.
The fluid-filled semicircular canals (labyrinth) attach to the
cochlea and nerves in the inner ear. They send information
on balance and head position to the brain. The eustachian
(auditory) tube drains fluid from the middle ear into the throat
(pharynx) behind the nose.
8. The inner ear is composed of:
three semicircular canals and otolith
organs - these control balance
the snail-shaped cochlea - this is the
hearing organ
9.
10. Cochlea
snail-shell like structure divided into
three fluid-filled parts. Two are
canals for the transmission of pressure
and in the third is the sensitive organ of
Corti, which detects pressure impulses
and responds with electrical impulses
which travel along the auditory nerve to
the brain.
11. The two fluids
Perilymph- fluid in the canals
Endolymph- fluid in the cochlear duct
is rich in potassium ions, which
produces an ionic, electrical potential.
