Download Balance - Mrs. Rugiel`s WIKI

Balance
By: Kristie, Aoife, Sierra
Sensory receptors
 Mechanoreceptors: receptors that respond to
gross movements of the head that disturb the
ear fluids surrounding the balance organs.
 Sensitive equilibrium receptors make the
nervous system aware of the position and
movements of the head. Without this balance is
impossible
 The inner ear is the only part that focuses on
balance.
Internal Ear structure
 Osseous labyrinth: bony chambers located within
temporal bone behind the eye socket. Has 3
subdivisions the cochlea, vestibule, and semicircular canals.
 The osseous labyrinth holds plasmalike fluid called
perilymph, that has membranous labyrinth suspended
in it. Suspended in membranous labyrinth is thick
fluid called endolymph.
Equilibrium
 Vestibular apparatus: the equilibrium receptors of the ear,
divided into two arms- static equilibrium and dynamic
equilibrium
 Static equilibrium: membrane sacs in vestibule that report on
changes of position of the head in space (with gravity) when
head is not moving, help keep head erect.
 Each macula has receptor “hair” cells in the otolithic hair
membrane- a jellylike mass studded with otoliths- tiny stones
made of calcium salts. As head moves, the otoliths roll with
gravity change, which pull the hairs, which send impulses to
the vestibular nerve to the cerebellum, saying where the
head is in space.
Equilibrium cont’d
 Dynamic equilibrium receptors are in the semicircular
canals. They respond to angle changes and rotations of the
head
 In the crista ampullaris, a receptor region, has hair cells and
the cupula- a gelatinous cap
 When head moves, endolymph canal stays behind, cupula
bends with body’s movement, which stimulates hair cells
and sends impulses to the vestibular nerve to the
cerebellum.
 When moving at a constant rate they stop sending impulses,
but continue again when there is change
Hearing and Equilibrium
Deficits
 Vertigo:
 “An unsteadiness sensation when walking, rotary
sensations, a sensation of being afloat on the air,
feeling of a hollow space in the head”
 Some autonomic symptoms such as sweating,
nausea, and vomiting are found to accompany
vertigo attacks
 Nystagmus: when the eyes move about
involuntarily. These symptoms and sensations can
occur at different random times and last temporarily,
or they can be persistent and last permanently.
Hearing and Equilibrium
Deficits cont’d
The vertigo problem can be derived from the ear or the brain:
 If it comes from the EAR it is termed peripheral. Peripheral causes
of vertigo include Meniere's Disease, ear trauma, labyrinthitis, and
Vestibular Neuronitis
 If the problem comes from the brain, then it is called central.
Central causes of vertigo include stroke/or tumor in the brainstem,
multiple sclerosis, migraine, drugs (sedatives), panic or anxiety, and
head trauma. Peripheral dizziness can be seen to be less severe of
the two because it does not severely affect the brain.
Hearing and Equilibrium
Deficits cont’d
 Meniere’s Syndrome:
 The most common causes of the disease are still
unknown
 Symptoms:
 Fluctuating hearing loss with distortion of sounds and
difficulty with speech discrimination
 Ringing in the affected ear (tinnitus)
Symptoms cont.
 A sense of the room spinning (vertigo)
 A cold sweat, nausea, and vomiting, or generalized
weakness during the attack The episodes are unpredictable
and usually last from 1 hour to a few hours, depending on the
severity of the disease
 Recurrence of the attacks is a cardinal feature of Ménière
disease. Typically the attacks are few, but the usual pattern
of Ménière disease is increasing frequency and severity of
the symptoms. The disease can be very disabling as the
frequency and severity of the attacks increases.