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16 Cards in this Set
- Front
- Back
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90% of the connections making up the cochlear division of CN XIII connect to what?
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inner hair cells, the principal sensory cells of the cochlea.
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What is the purpose of outer hair cells?
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To lower the threshold of excitation of inner hair cells.
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Obstruction, otitis media, and otosclerosis can cause which type of hearing loss?
Meniere dz, vestibular schwannoma, and age-related hearing loss (presbycusis)? |
conductive
sensorineural |
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What are the two subsystems of the vestibular system, and what are their components?
What is an otolith? |
static labyrinth
- utricle - saccule kinetic labyrinth - 3 x semicircular ducts Membrane that has higher specific gravity than the surrounding endolympth. |
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Bending the vesticular hair cells *towards* the kinocilium causes ______, where as bending *away* causes _______.
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excitation
inhibition |
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What is the pathophysiology of motion sickness?
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The static labyrinth can respond somewhat to linear acceleration due to it's structure... prolonged, fluctuating stim of the static labyrinth is known to cause motion sickness.
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Why don't the semicircular ducts respond to changes in head position? What do they respond to?
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the cupula that the hair cells extend into has the same specific gravity as the endolymph surrounding it.
Acceleration in a particular plane. |
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What is the cristae ampullaris? What are maculae?
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where the hair cells and associated structures are located for the kinetic labyrinth and the static labyrinth, respectively.
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What are the two components of nystagmus? Which gives the naming convention for direction? What etiology accounts for the other portion of nystagmus?
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Fast and slow.
The direction of the 'fast' determines the named direction of the nystagmus. The slow components is the reflex correction by the vestibular system to restore direction of gaze. |
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With cold water irrigation in the L ear, give the results found in the following situations:
- Conscious pt - comatose pt w/ brainstem intact - bilateral MLF lesion - comatose pt with brainstem lesion |
- slow deviation towards L; fast nystagmus away
- slow deviation L, no nystagmus - L eye ONLY slow dev. L, no nystagmus - both fast and slow phases are absent |
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The parts of the brain responsible for olfaction are collectively called what?
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rhinencephalon.
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What is the path of the olfactory nerves up into the brain?
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pass through the cribiform plate of the ethnmoid bone --> join on olfactory bulb & excite glutaminergic interneurons --> mitral cell axons project through the olfactory tract --> most fibers go to the lateral olfactory area, the remainder to the intermediate olfactory area
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What is included in the lateral olfactory area? What is another name for these areas? Where do they send fibers?
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uncus, entorhinal area cortex, some limen insulae cortex, and part of the amygdala
- primary olfactory area - olfactory association cortex on the lateral part of the cortical orbital surface |
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What fibers, originating from the contralateral olfactory bulb and the nucleus of the diagonal band are important for modulating the *sensitivity* of the olfactory system?
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centrifugal fibers.
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In what 3 places are taste buds located?
Localize the following to where they are *most* prevalent: - sweet - sour - bitter - salty - metallic |
soft palate, epiglottis, and dorsal tongue.
- sweet ~ tip - sour ~ lateral edges - bitter ~ back of tongue - salty ~ middle of tongue - metallic ~ all over tongue |
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What nerves innervate taste on the tongue?
What nucleus do efferent fibers synapse in? |
VII = ant. 2/3rds and soft palate
IX = post 1/3rd X = small part of epiglottis Solitary nucleus (rostral portion) |
