Term
The Organ of Corti is composed of both sensory and support cells. T/F |
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Definition
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Term
The outer hair cells comprise 3-6 rows and number at least 15,000-25,000. T/F |
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Definition
False OHC are usually 3-4 rows and 12,000-20,000 |
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Term
What is the primary blood supply to the cochlea? |
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Definition
The internal Auditory Artery |
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Term
For a normal adult, describe the structure and length of the cochlea. |
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Definition
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Term
What are the two primary fluids contained within the cochlea? |
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Definition
Endolymph and perilymph. Endolymph is high in potassium & low in sodium. Perilymph is high in sodium and low in potassium. |
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Term
The Scala Media is separated from the Scala Tympani by what structure? |
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Definition
Basilar membrane. Scala media has endolymph, scala tympani has perilymph. |
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Term
Outer hair cells receive about 5% of the innervation of the nerve fibers from the acoustic portion of the VIIIth nerve. T/F |
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Definition
True IHC receive about 95%, while OHC receive about 5% |
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Term
The scala tympani and the scala vestibuli communicate through a small opening within the cochlea which is called ___________________. |
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Definition
Helicotrema This is located at the apex of the cochlea and where the perilymph from the scala tympani and scala vestibuli communicate. |
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Term
The stria vascularis is the major anatomical site within the cochlea that is highly invovled in the metabolic activity associated with perilymph production and maintenance. T/F |
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Definition
False. ( The stria vascularis is important for endolymph production and maintenance. Additionally, very important in the OAE production.) |
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Term
The scala media is the first to receive the vibrations of the stapes footplate in the oval window resulting from acoustical stimulation. T/F |
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Definition
False The scala vestibuli is the first to receive the input from the stapes footplate. |
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Term
The membraneous labyrinth attaches to what structure? |
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Definition
Osseous spiral lamina. The membraneous labyrinth attaches to the bony layrinth and to the bony shelf, the osseous spiral lamina projecting from the modiolus. |
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Term
Outer hair cells are located on the spiral lamina. T/F |
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Definition
False They are located on the basilar membrane. |
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Term
OHC are test tube shaped and highly motile. T/F |
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Definition
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Term
What is the percentage of people who will have spontaneous emissions and what frequency range are you likely to see them? |
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Definition
50-70% of normal hearers will have SOAE, typically in the 1-2kHZ range. If present, likely to be present in both ears. |
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Term
Spontaneous emissions are consistent with "objective tinnitus". T/F |
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Definition
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Term
Stimulus Frequency OAEs are clinically the most utilized OAE test. T/F |
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Definition
False They are not used clinically at all. DPOAEs are the most popular. |
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Term
The ionic composition of the endolymph contained within the scala media gives rise to an electrical potential called ________________. |
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Definition
The endocochlear potential.(This is an electrochemical battery created by the stria vascularis that plays a role in cochlear transduction.) |
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Term
The discovery of OAEs is credited to which person? |
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Definition
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Term
The Organ of Corti contains two distinctive types of sensory cells. What are they called? |
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Definition
Inner and Outer Hair Cells. IHC are purely sensory, while OHC are both sensory but have motor capablities as well. |
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Term
Which company developed the first OAE equipment? |
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Definition
Otodynamics in 1988. GSI and Madsen introduced equipment in the early 1990's. |
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Term
The first comprehensive descriptions of OAEs were published in 1977 and the first CPT code in 1994. T/F |
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Definition
False Kemp published in 1978 and first CPT code in 1995. |
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Term
Descirbe the inward energy propogation from pinna to cochlea as it relates to OAEs. |
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Definition
acoustic-mechanical-bioelectric |
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Term
The foundations for the discovery of OAE was developed by whom? |
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Definition
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Term
Efferent innervation influences OHC and thus influences OAEs. T/F |
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Definition
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Term
OHC motility and the large number of OHC are believed to be the contributor to the cochlear amplifier theory. T/F |
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Definition
True As proposed by Hallowell Davis in 1983. |
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Term
What is the correct order of the ossicles in relationship to the tympanic membrane & moving medial towards the cochlea? |
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Definition
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Term
OHC contract (shorten) when their membrane is depolarized and elongate (lengthen) when hyperpolarized. T/F |
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Definition
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Term
TEOAEs are elicited by presenting a short-duration pure tone into the ear. T/F |
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Definition
False. They use a click, tone burst or tone pip. |
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Term
The normal cochlear process can be described as a nonlinear system. T/F |
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Definition
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Term
A thin layer of cells known as ____seperates the scala vestibuli from the scala media. |
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Definition
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Term
The tympanic membrane consists of two layers of tissue. T/F |
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Definition
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