Term
3 Primary Function or tasks of the vestibular system (VS):
1. Acts to provide information to the central nervous system for controlling and adjusting muscle ___ and ___
2. Stabilizes the ___ environment during motion of environment or person
3. Provides CNS with spatial information regarding ___ and ___ movements |
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Definition
1. tone; posture
2. visual
3. linear; angular |
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Term
Fluids found in the VS:
1. Bony labyrinth filled with ___. Similar to ___ fluid. Has a high ___ to ___ ratio
2. Membranous labyrinth filled with ___. High ratio of ___ to ___. Houses vestibular ___ ___. |
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Definition
1. perilymph; cerebrospinal; sodium; potassium
2. endolymph; potassium; sodium; sensory organs |
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Term
| Where is the crista ampullaris housed? |
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Definition
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Term
| Each semicircular canal has an enlarged end called the ___. |
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Definition
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Term
| What are 2 important structures in the crista ampullaris? |
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Definition
| The cupula and the type 1 and type 2 hair cells. |
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Term
| The crista ampullaris is shaped like a ___. |
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Definition
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Term
Crista Ampullaris:
-The cupula is a ___ mass that extends from the base of the ampulla to the roof and effectively ___ ___ the two sides of the ampulla.
-Embedded in the base of the cupula are the ___ of the type 1 and type 2 receptor hair cells. |
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Definition
| gelatinous; seals off; stereocilia |
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Term
-How many hair cells are in each cupula?
-How are they polarized? |
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Definition
| 7000; in the same direction |
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Term
In the cupula, a deflection of the hair cell bundle toward the kinocilium results in an ___ (___) in firing rate of the affect fibers connected to the hair cells.
-Deflection of the stereocilia bundle away from the kinocilium results in ___ (___) in neural afferent firing rate |
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Definition
| increase (excitatory); decrease (inhibitory) |
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Term
-The stereocilia in the vertical canals (anterior and posterior) are polarized toward the ___ side of the ampulla. The stereocilia in the horizontal canals are oriented toward the ___ side of the ampulla.
-In the horizontal canals, movement of endolymph toward the ___ (___) generates an increase in firing rate in the nerve while in the vertical (anterior and posterior) canals the ___ is true (endolymph flow toward the ampulla results in the decrease firing rate; this is called ampulofugal). |
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Definition
| canal; utricle; ampulla (ampullopetal); opposite |
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Term
| What does ampullopetal mean? What does ampullofugal mean? |
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Definition
| Ampullopetal (utricopetal)-toward the ampulla or utricle. Ampullofugal-away from the ampulla |
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Term
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Definition
| The horizontal canals are coplanar pairs. Pairs for the vertical canals: right anterior with left posterior (RALP) and left anterior with right posterior (LARP). |
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Term
Examples of the coplanar pairs at work:
1. When the head is moved quickly to the right in the horizontal plane the ___ horizontal canal is excited and the ___ horizontal canal is inhibited.
2. When you do a head nod forward while angled to the right the ___ ___ SCC is excited while the ___ ___ SCC is inhibited |
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Definition
| right; left; right anterior; left posterior |
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Term
-The type 1 hair cells produce an ___ firing pattern and are found to be clustered in the ___ of the crista. It's been suggested that they might be responsible for producing ___ ___ of neural activity that adjust the head when the canals are stimulated.
-Type 2 neurons are found to be located on the ___ of the crista and have been suggested to be primarily responsible for driving the eye movement of the ___ ___. |
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Definition
| irregular; center; quick bursts; periphery; vestibuloocular reflex (VOR) |
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Term
Otolith (macular) organs:
-These two organs are called the ___ and ___
-Both have a sensory epithelium called a ___
-The utricular macule is oriented in the ___ plane and lies near the ___ opening of the horizontal SCC.
-The macule of the saccule is oriented primarily in the ___ plane and is located on the medial wall of the vestibule inferior to the ___ |
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Definition
| saccule; utricle ;maculae; horizontal; anterior; vertical; utricle |
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Term
| The ___ act as the mass in the utricle and the saccule. The crystals are dense compared with the surrounding endolymph and therefore have a ___ specific gravity. |
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Definition
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Term
-The utricle is sensitive to a change in ___ movement, and the saccule gives information about ___ acceleration (such as when in an elevator).
-The otolith organs, which are the other part of the vestibular system, are two pouches that are also filled with ___. They sit ___ below the semicircular canals and have a similar function.
-These two pouches are also lined with small ___. Small crystals attached to the hairs move through the fluid when the head ___. When this happens they ________________, which sense this movement and then send nerve signals to the brain |
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Definition
| horizontal; vertical; fluid; sideways; hairs; tilts; rub along the hairs |
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Term
| Both the saccule and utricle have a central region called a ___ that divides the organs into 2 parts. |
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Definition
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Term
Motion that stimulates the otolith organs:
-Saccule: More involved in ___ linear acceleration. The kinocilia is oriented ___ from the striola.
-Utricle: More involved in ___ linear acceleration. The kinocilia is oriented ___ the striola.
-Linear movement will cause ___ of organ to be stimuluated and half to be inhibited (creating ___ ___ within the organ)
-Half of the organ is ___ and half is ___. |
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Definition
| vertical; away; horizontal; toward; half; coplanar pair; excited; inhibited |
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Term
Innervation:
-Superior vestibular nerve innervates the ___ and ___ SCC, and the ___
-Inferior vestibular nerve innervates the ___ SCC and the ___
-Between ___ and ___ vestibular nerve fibers in human (range may be function of age)
-Branches travel together into the ___ junction and then bifurcate |
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Definition
| horizontal; anterior; utricle; posterior; saccule; 15,000 and 25,000; ponteomedullary |
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Term
Blood Supply: -The superior vestibular artery supplies the ___, ___ SCC, and the ___ SCC
-The inferior vestibular artery supplies the ___ and ___ SCC |
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Definition
| utricle; horizontal; anterior; saccule; posterior |
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Term
| What are the 4 primary vestibular nuclei? |
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Definition
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Term
| What type of info is processed in the IVN, LVN, SVN, and MVN? |
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Definition
-IVN=Autonomic control and balance/posture
-LVN=Balance and posture and eye movements
-SVN=Eye movement
-MVN=alance/posture, autonomic control, cognition, and eye movement. |
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Term
| What are the shapes of the 2 types of hair cells? |
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Definition
Type 1=flask shaped
type 2=cylindrical shape |
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Term
Vestibular reflexes:
-Vestibulo-Ocluar Reflex: Must generate rapid compensatory eye movement in the ___ direction of head rotation to maintain image on fovea or retina. We measure ___ and ___. |
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Definition
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Term
Vestibular reflexes: Vestibulospinal Reflex
-Acceleration of the head (in addition to VOR) causes an upper and lower ___ response
-Limbs ipsi to direction of acceleration are ___; and those contra are ___
-Purpose to maintain ___ and center of mass over ___ of support
-Adjust posture to remain ___. Like when you are on the monorail and you shift your weight to one side to stay upright. |
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Definition
| limb; extended; contracted; posture; base; upright |
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Term
Vestibular reflexes: Vestibulocolic Reflex
-A “___” reflex
-Assists in maintaining the head in ___ gaze orientation relative to gravity and independent of ___ movement
-May be mediated through ___ organs and ___ vesibulospinal tract |
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Definition
| righting; horizontal; trunk; otolitic; medial |
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Term
| What's an example of the vestibulocolic reflex? |
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Definition
| When you fall and you continue to look upright |
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Term
| What is the purpose of each reflex? |
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Definition
-Vestibulo-ocular reflex=Used to stabilize gaze during head movement. Also used to measure cVEMP
-Vestibulospinal reflex – used to make postural adjustments
-Vestibulocollic reflex – used to respond quickly To intense sounds with head turns |
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Term
Velocity Storage:
-Signal generated by movement of cupula is brief and lasts only as long as the ___ is deflected
-Response is sustained by a circuit of neurons in the ___ vesibular nucleus and lasts longer than __ seconds in the people with normal vestibular function
-Believed to sustain the vestibular input to assist the brain in detecting low-frequency ___ ___
-Spin in circle for ___ minutes. After ___ seconds the patient won’t feel like they are spinning. When they actually stop spinning then it will feel like they are spinning in the ___ ___ because the fluid is catching up. Physical properties and fluid mechanics cause vestibular generated response to fatigue in __ to __ seconds
-Healthy velocity storage mechanism causes response to continue to about __-__ seconds |
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Definition
| cupula; medial; 10; head rotation; 1.5; 10; opposite direction; 6 to 7; 15-20 |
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