Vestibular System Flashcards
Which of the following components of the vestibular system found in the inner ear and is responsible for relaying head postion and motion via APs?
A. Vestibulothalamocortical Network
B. Central Cestibular Nuclei
C. Peropheral Receptor Apparatus
D. Vestibulospinal Network
E. Vestibuloocular Network
eropheral Receptor Apparatus
Which of the following components of the vestibular system is found within the brainstem and is responsible for integrating and distributing information needed to control motor activity and have spatial awareness?
A. Vestibulothalamocortical Network
B. Central Cestibular Nuclei
C. Peropheral Receptor Apparatus
D. Vestibulospinal Network
E. Vestibuloocular Network
Central Cestibular Nuclei
Which of the following components of the vestibular system is found within is involved in the control of eye movements while the head moves?
A. Vestibulothalamocortical Network
B. Central Cestibular Nuclei
C. Peropheral Receptor Apparatus
D. Vestibulospinal Network
E. Vestibuloocular Network
Vestibuloocular Network
Which of the following components of the vestibular system coordinates the head movements with the acial and postural muscles?
A. Vestibulothalamocortical Network
B. Central Cestibular Nuclei
C. Peropheral Receptor Apparatus
D. Vestibulospinal Network
E. Vestibuloocular Network
Vestibulospinal Network
Which of the following components of the vestibular system is involved with awarebess of movement and spatial orientation?
A. Vestibulothalamocortical Network
B. Central Cestibular Nuclei
C. Peropheral Receptor Apparatus
D. Vestibulospinal Network
E. Vestibuloocular Network
Vestibulothalamocortical Network
There are two major vestibular receptor organs that include the Semicircular canals and the otolithic organs of the utricle and saccule.
What head movements are detected by the Semicircular canal?
What head movements are detected by the otolithic organs of utrcle and saccule?
Semicircular Canal: Angular acceleration (rotational head movements)
Utricle and Saccule: Linear Acceleration (translational head movements)
Receptor cells that leave the vestibular organs (semicicurclar canals and utricle/saccule) are innervated by primary afferent fibers from what ganglion?
In general, the central processes of these fibers enter the brainstem and terminate on what two structures?
Vestibular Ganglion (Scarpa ganglion)
Ipsilateral vestibular nuclei and cerebellum
In general what leads to vestibular disease?
A. Disturbances in volume of endolymph
B. Disturbances in ion concentration of perilymph
C. Disturbance in volume and ion concentration of endolymph
D. Disturbacnes in volume and ion concentration of perilymph
Disturbance in volume and ion concentration of endolymph
What artery is the primary supply of the vestibular apparatus?
What artery also feeds the semicircular canals, but is not the primary source?
Labyrinthine A. (branch of the AICA that enters through Internal Auditory Meatus)
Stylomastoid A.
Interuption of the Labyrinthine A. will compromise the vestibular organs leading to what types of presentation/symptoms?
Vertigo
Nyastagmus
Unstable Gait

Meniere’s disease presnts with symptoms of fluctuating hearing loss, vertigo, positional nyastagmus, and nausea. What causes this disease to develop?
What are some treatments for this disease?
Disruption in the normal endolymph volume that leads to endolymphatic hydrops, also known as an abnormal distention of the membranous labyrinthe=
Treatment includes a diuretic or salt restricted diet, or possibly adding a shunt to drain the swollen sac

Hair cells determine positional changes as they are moved by endolymph. There are two types of hair cells Type I and Type II, that have no real significant difference except for what?
What nerve innervates these hair cells?
Type 1 has one large nerve terminal connection (nerve calyx)
Type 2 hair cells make several individual connections/synapse

The movement of sterocilia (hair cells) towards or away from the kinocelium is what activates or registers the vestibular system.
What direction does the sterocilia need to move in order to depolarize and activate?
Hyperpolarize and inhibit?
Sterocilia TOWARDS kinocelium results in depolarization and activation
Sterocilia AWAY from jinocilium results in hyperpolarization and inhibition
Correctly describe the detection mechanism that occurs within the semicircular canal. Start by describing the anatomical relationship of the structures involved
The semicircular canal contains the ampulla, where hair cells are located inside and embedded on the cristae along the base of the ampulla. Hair cells extend into the cupula.
Rotational/angular acceleration moves the endolymph causing it to displace the cupula. The movement of the cupula displaces the hair cells, which are then excited or inhibited depending on direction

Correctly describe the detection mechanism that occurs within the utricle and saccule. Start by describing the anatomical relationship of the structures involved
The utricle and Saccule contain the maculae. Inside the maculae are sterocilia that extend into the otolith membrane. The otolithic membrane is covered by otoconia (ear stones).
Gravity/Linear acceleration displaces the otoconia and bends the underlying sterocilia

Nerves leaving the the ampulla and the maculae converge as what primary afferent fiber before entering what junction found within the brainstem?
CN VIII
Pontomedullary Junction
Secondary vestibular afferents leave the pontomedullary junction and project to what nuclei?
What information do these nuclei encode?
Vestibular Nuclei (superior, medial, lateral, inferior)
Direction
Speed of movement
Head position

The secondary neurons that leave the vestibular nuclei target what 3 cranial nerve nuclei?
What other four 4 structures are targets so that we can integrate information?
CN: 3, 4, 6
Vestibulocerebellum
Spinal Cord
Reticular Formation
Thalamus
Vestibulovestibular fibers are secondary fibers that make reciprocal connections with analagous contralaterally located nuclei. Which of the following correctly expresses what these fibers signal when the head turns right?
A. Left afferents are inhibited, right afferents are inhibited
B. Left afferent are inhibited, right afferents are inhibited
C. Left afferents activated, right afferents activated
D. Left afferents are inhibited, right afferents are activated
Left afferents are inhibited, right afferents are activated
Spinovestibular fibers arise from all spinal cord levels to provide what type of input?
A. Nociceptive
B. Proprioceptive
C. Discrimintive touch
D. Pain and temperature
Proprioceptive


Look at it Again
What is the only sensory organ body that sends direct projections to the cerebellum?
Vestibulocerebellar Fibers
There are primary and secondary vestibulocerebellar fibers that course through thejuxtaretiform body found inthe inferior cerebellar peduncle.
What do the primary vestibulocerebellar fibers target?
What do primary vestibulocerebellar fibers terminate as?
What do secondary vestibulocerebellar fibers target?
Primary Vestibulocerebellar Fibers
- Target: Dentate nucleus
- Terminate: Mossy fibers
Seondary Vestibulocerebellar Fibers
- Flocculondular Lobe
- Fastigial Nuclei
- Dentate Nuclei
What is dizziness?
A nonspecific term that general refers to spatial disorientation




