Vestibular System Flashcards
Inputs of the vestibular system
visual
pressure receptors in the feet
vestibular organ in the inner ear
Where is the vestibular organ in the ear and what is it called
In the temporal bone near the ear and is called the posterior labyrinth
Wh]]]What are the 5 organs in the posterior labyrinth
Utricle, saccule and the 3 semi circular canals (anterior, posterior and lateral)
What is connected to the utricle
the 3 semi circular canals and the saccule
Which 2 canals are connected
Anterior and posterior
What is connected to the saccule
the utricle and the cochlear
what liquid is outside the membranous labyrinth
perilymph
what liquid is inside the membranous labyrinth
endolymph
What are the 2 types of hair cell and which is more abundant, how direct is the afferent and efferent inputs and outputs
type 1, more abundant, direct afferent and indirect efferent
type 2 is direct afferent and efferent
What are the otolith organs
utricle and saccule
What are otoliths
carbonate crystals
Where is the macula in utricle
Lower part
Where is the macula in saccule
side pointing to the spiral of the cochlear
what is found in the otolith organs and what are the otolith organs (3)
hair cells, otoliths and a gelatinous matrix, the saccule and utricle
Where are otoliths found in the otolith organs
On top of the gelatinous matrix inside the saccule and utricle
What is the purpose of the otolith crystals in the saccule and utricle
When you move your head the move on the gelatinous matrix and apply levels of pressure to the hair cells below deflecting them
What are striola and where is it found
Opposing hair bundle polarities, found in the centre of the otolith organs (saccule and utricle)
Direction of the kinocilium in the utricle, and how do they depolarise
facing towards each other, depolarise when hair deflects in the direction of the striola
Direction of the kinocilium in the saccule, and how do they depolarise
away from each, deflection away from the striola depolarises it
Where are kinocilium facing towards the striola found
Utricle
Where are kinocilium facing away from the striola found
Saccule
Where is the cupula of the semi circular canal
in the wider parts of the semi circular canal, closes these wider bits off
what are the longest cilium known as
Kinocilia
What is the ampulla of the semi circular canal
inside of the cupula
Where are hair cells found in the semi circular canal
in the crista of the ampulla inside the cupula
What is the cupulla
A kind of gel but not as thick as the gelatinous matrix of the otolith cells
How are hair cells in the endolymph deflected
When we move the endolymph pushes against the cupula which deflects the hair cells
What direction is the anterior semi circular canal (say degrees for ease and straight ahead is 0) and what plane
about 45 degrees either way vertical
What direction is the posterior semi circular canal (say degrees for ease and straight ahead is 0) and what plane
225 degrees either way, vertical
What direction is the lateral semi circular canal (say degrees for ease and straight ahead is 0) and what plane
90 degrees and horizontal
What is the blood supply to the vestibular organ
Anterior inferior cerebellar artery (AICA)
2 afferent vestibular nerves?
superior and inferior vestibular nerves
Superior vestibular supplies … (3)
utricle and the anterior and horizontal canals
Inferior vestibular supplies … (3)
saccule and the posterior canals
The afferent output of the utricle is through the ..
Superior vestibular nerve
The afferent output of the saccule is through the ..
inferior vestibular nerve
The afferent output of the horizontal canal is through the ..
superior vestibular nerve
The afferent output of the anterior canal is through the ..
superior vestibular nerve
The afferent output of the posterior canal is through the ..
inferior vestibular nerve
The superior and inferior vestibular nerves travel to X in the Y
vestibular nuclei in the Brain stem
What are the 4 vestibular nuclei
Superior
lateral
medial
inferior
the static labyrinth is also known as …
otoliths
the kinetic labyrinth is also known as…
Semi circular canals
the static labyrinth feeds into what part of the vestibular nucleus
lateral and inferior
the kinetic labyrinth feeds into what part of the vestibular nucleus
superior and medial
the Semi circular canals feeds into what part of the vestibular nucleus
superior and medial
the otoliths feeds into what part of the vestibular nucleus
Lateral and inferior
Lateral and inferior vestibular nucleus has information coming from …
otoliths/static labyrinth
superior and medial vestibular nucleus has information coming from …
Kinetic labyrinth/SCC
Vestibular nuclei projects to … (6)
spinal cord nuclei of the extra ocular muscles cerebellum centres of CVS and resp control thalamus superior parietal cortex
Where is the vestibular cortex
Parietal cortex
What does the cerebellum do in the vestibular system (3)
Movement coordination
posture regulation
eye movements
main functions of the motor output in the vestibular system? (3)
detect and inform head movements
keep images fixed in the retina during head movments
postural control
What is the constant firing of the vestibular system known as
Resting discharge
What happens if the kinocilium move in the opposite direction for polarisation
Inhibition/hyperpolarisation
which otolith organ is responsible for detecting horizontal linear accelation
The utricle
which otolith organ is responsible for detecting vertical linear accelation (tilt)
Saccule
which vestibular organ is responsible for detecting angular accelation and what causes angular accelaration
semicircular canals
turning the head
Direction of liquid movement in SCC vs head movement
they go opposite directions
SCC canals work in ….
Pairs (opposite canals attract, apart from both horizontal ones lol)
What are the 2 vestibulospinal reflex
Lateral and medial
is the lateral vestibular spinal tract contra or ipsilateral or both
Ipsi
is the medial vestibular spinal tract contra or ipsilateral or both
both
the medial vestibular spinal innervates muscles where (3)
neck and back
the lateral vestibular spinal innervates muscles where
limbs
what is the function of the vestibulospinal tract
to keep you from falling
what is the function of the vestibulo ocular tract
To keep image fixed
vestibulo ocular tract connects which nuclei
Vestibular and occulomotor
Fastest reflex in the eye?
vestibulo ocular
What causes nystagmus
Unilateral lesion in one of the SCC
What needs to be checked to make a vestibular diagnosis: 7
Patient history balance and gait assessment cerebellum gaze assessment: eye movements vestibular tests Imaging Questionnaires
Symptoms of vestibular disease:
)Vertigo
Dizziness
Unsteadiness
Self-motivation perception
Peripheral vestibular disease affects… (2)
labyrinth and VIII nerve
Central vestibular disease affects… (2)
Brainstem/cerebellum
Examples of Peripheral vestibular disease
vestibular neuritis
Examples of central vestibular disease (3)
stroke/MS/tumours
Example of acute vestibular disease
vestibular neuritis
Example of intermittent vestibular disease
BPPV
Example of recurrent vestibular disease
migraine
Example of progressive vestibular disease
Acoustic VIII nerve neuroma
