Exam 3 vestibular Flashcards
Three functions of the vestibular system
balance/postural control
spatial relationships (are we moving or stationary)
keep vision stable when head is moving
% of vestibular issues and age groups
40% in >40 y/o
80% 65+ have experienced dizziness
How much vertigo in vestibular problems?
accounts for 1/3 of all dizziness
Peripheral Vestibular disorders hyperfunction
BPPV benign paroxysmal positional vertigo
characterized by spinning
Three components of the ear
outer ear- auricle and external auditory canal
middle ear- air space + malleus, incus, and stapes
inner ear- embedded in petrous portion of temporal bone. Vestibule, cochlea, SCC, otolithic organs
Layers of SCC
bony labyrinth, perilymph fluid(continuous with CSF), membranous labyrinth, endolymph fluid
sensitive to angular acceleration.
Otolithic organs
inside the vestibule–sensitive to linear accel/decel and gravity
utricle- horizontal plane
saccule- vertical plane
Types of SCC
Horizontal- tilted up 30 degrees
Anterior 90 from the horizontal
Posterior 90 from the horizontal
What is the ampulla and where is it?
the bulbous end of the SCC where the hair cells are located.
cupula is the inner portion of the ampulla where the hair cells project up into it.
Kinocilium
the most medially positioned hair cells in the horizontal canals that sense the movement of the endolymph
Rotation to the right
will cause endolymph to move left–causing more excitement(depolarization) on the right and less excitement(hyperpolarization) on the left.
where are hair cells in otolithic organs?
on the macula–they project up into the otolithic membrane where the otoconia crystals sit and provide weight to make the otoliths sensitive to gravity.
