midterm Flashcards
(105 cards)
common causes of vestibular disorders
head trauma, otitis media, bacterial labyrinthitis or vestibular neuronitis, viral labyrinthitis or vestibular neuronitis, ototoxic medications, ischemia, vestibular schwannoma or viral causes
impact of dizziness and balance on the population
dizziness is the 3rd most common complaint within outpatient clinics and the #1 complaint in individuals over the age of 70
-additionally, half of the people over the age of 70 will experience BPPV
how is dizziness often reported by our patients
vertigo, syncope, lightheadedness, disequilibrium, unsteady, floating, rocking, tilting, foggy feeling, motion sickness, etc.
true vertigo
the room is spinning or you are spinning
-all about rotation
the ability to maintain balance depends upon ….
sensory information gathered from visual, somatosensory and vestibular receptors within the body
-the sensory information is picked up and set to the brainstem for integration and then sent up to the cortex for perception and processing
how do the cerebellum and cerebral cortex streamline the balance process
they coordinate incoming impulses and add that information from thinking and memory
peripheral vs. central
inner ear (labyrinth to the brainstem) vs. the CNS (brainstem to the cortex)
vision denied
patient does not have a visual target, eyes are closed or covered
vision allowed
patient has a visual target, eyes are open or uncovered
role of the peripheral vestibular system
allows us to interact and maintain contact with our surroundings in a safe, efficient manner
the labyrinth
interconnected canals and cavities that are located in the petrous portion of the temporal bone that houses the sensory organs
bony labyrinth vs. membranous labyrinth
the outer wall vs. inside the bone and suspended in fluid
perilymph vs. endolymph
fluid within the labyrinths that is similar to CSF vs. fluid inside of the membranous labyrinth
how many sensory structures are there total
10 ; 5 on each side
-3 SCC, 1 utricle and 1 saccule
semicircular canals (SCC) overview
bony tubes that are interconnected and oriented as right angles of each other allowing the endolymph to flow to or from the ampullated end of the canal
-3 per canal
-responsible for the pitch, yaw and roll movement
SCCs are primarily responsible for detecting ……
angular accelerations and decelerations of the body
the sensory cells of the SCCs are the …..
cristae ampullaris
what is the cupula and what is happens if the density is changed
it sits on top of the cristae containing the same density as the endolymph
-if anything that impacts the density, this will cause an illusion of vertigo due to stimulation
vestibular hair cells
these are stimulated by the movement of the SCC and the position relative to gravity
-they have kinocilium and several stereocilia containing a resting potential when at rest but with any motion this will change the potential
any movement that causes the sterocilia to flow towards the kinocilium results in ……
depolarization with an increased potential
any movement that causes the sterocilia to flow away from the kinocilium results in ……
hyperpolarization with a decreased potential
how are vestibular hair cells oriented in the SCC canals
in anterior and posterior : towards the canal side of the ampulla
in horizontal : towards the utricle
how does the horizontal canal become inhibited and excited
movement of endolymph away from the ampulla causes inhibition and movement towards the ampulla causes excitation
how does the anterior and posterior canals become inhibited and excited
movement of endolymph towards the ampulla causes inhibition and movement away from the ampulla causes excitation