Term
What are the four components to the peripheral sensory apparatus? |
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Definition
Horizontal, anterior and posterior canals, and a central chamber (vestibule). |
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Term
What does the Central processor consist of in the vestibular system? |
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Definition
Vestibular nucleus complex, and the cerebellum. |
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Term
What is the job of the cerebellum in the central processing unit? |
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Definition
it serves as the adaptive processor. |
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Term
Where does the central processing unit send info to? (2 places) And what do each of these places do with the information? |
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Definition
Ocular muscles, for the VOR. Spinal cord for VSR. |
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Term
Shaking the head stimulates which of the three canals? |
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Definition
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Term
What three pieces of information is the peripheral sensory apparatus responsible for? |
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Definition
Head angular velocity, linear acceleration, and orientation of the head in relation to gravity. |
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Term
Nodding the head primarily stimulates what canal? |
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Definition
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Term
What are the two otolith organs, and what are their functions? |
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Definition
Utricle - horizontal movement, and Saccule - vertical movement. |
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Term
Where do you find perilympatic fluid? Endolymphatic fluid? How do these two interact? |
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Definition
Peri: Between the bony portion and membranous portion of the semicircular canal. Endo: within the membranous portion of the semicircular canals. There is NO communication between these two substances. They are completely separated by the membrane with the canals. |
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Term
What is the ampulla, and where is it located? |
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Definition
The ampulla is an enlargement at the bottom of each end of the semicircular canal. It contains the crista and cupula. |
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Term
Where is the Crista, and what is its purpose? |
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Definition
It is attached to the bottom of the ampulla. Hair cells at the base of the ampulla project into the crista. |
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Term
What is the cupula? Describe it, where it is and its function. |
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Definition
It is attached to the bottom of the ampulla, on top of the Crista. Hair cells project through the crista into the cupula which is a gelatinous membrane. When there is endolymphatic flow, the cupula sways and bends the hair cells. |
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Term
Does the cupula respond to gravity? |
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Definition
No. only to endolymphatic flow. |
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Term
What are stereo and kinocilium? Where are they and how do they relate? |
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Definition
They are hair cells that project into the cupulla. There are 40-70 stereocilia, and 1 kinocilium in the cupula. The kinocilium is the tallest, and when the stereocilia deflect toward it there is excitation of the nerve. When they deflect away, there is inhibition of nerve activity. |
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Term
How does head movement relate to endolymph flow? |
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Definition
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Term
What does the vascular supply look like to the vestibular unit? |
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Definition
Basilar -> Ant Inf Cerebellar Artery -> Labyrinthine Artery -> vestibular and common cochlear arteries. (Labyrinthine A may also be a direct branch from the basilar. |
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Term
Is there collateral vascular network for the vestibular apparatus? |
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Definition
No. So if there is an infarct in the AICA or the pons, there can be vestibular problems. |
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Term
Where are the vestibular nuclei located? |
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Definition
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Term
What is the specific function of the cerebellum as it relates to the vestibular network? |
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Definition
It receives vestibular nuclei input and sends output to the body. Adjusts the size/magnitude of reaction and coordinates smoothness of response to vestibular input. |
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Term
What parts of the inner ear are responsible for recognition of rotational movement? |
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Definition
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Term
What parts of the inner ear are responsible for detection of linear acceleration? |
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Definition
otoliths; utricle (horizontal) and saccule (vertical). |
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