Auditory/Vestibular Anatomy Flashcards Preview

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Flashcards in Auditory/Vestibular Anatomy Deck (12)
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2 Nerves of Ext Ear

Mostly V3, some X


2 Main Sections of Tympanic Membrane

Pars flaccida and tensa (larger, vibrates)


2 Windows

Oval which stapes pushes against and round as relief valve


Vestibular N VIII

Bipolar cells that go to vestibular nuclei (or some project to cerebellum)


3 Adjacent Ducts in Cochlear System

Scala vestibuli and tympani - perilymph filled
Scala media - endolymph filled



End of cochlea where scala vestibuli and tympani meet


Propagation to Hair Cells

Sit on organ of Corti (in scala media) which is on basilar membrane b/w media and tympani. As perilymph in tympani moves, moves basilar membrane, pushing organ of Corti and hair cells against tectorial membrane, opening them


Cochlear Pitch Differentiation

Different Hz/wavelengths vibrate different parts of cochlear ducts. High pitches near round window and low pitches near helicotrema


Cochlear Nervous Pathway

Bipolar axons from cochlea, vestibulocochlear n. VIII w/ cell bodies in spiral ganglia, dorsal and ventral cochlear nuclei, 2nd order form dorsal and ventral cochlear nuclei, some cross at trapezoid body (goes up bilaterally), some synapse in superior olivary nuclei, ascend in lateral lemniscus to inferior colliculus (synapse), brachium of inferior colliculus to medial geniculate nucleus for thalamic relay, then auditory cortex


Left/Right Sound Descrimination

Each side bilaterally goes to each superior olive. It takes longer for signal from opposite side to reach, so it calculates which side the sound is on


Lesion in Internal Acoustic Meatus Effects

Hearing/vestibular/VII - taste ant 2/3, parasymp to non-parotid glands, etc gone


Acoustic Neuroma

Tumor in inner ear that bulges out, but puts pressure on VII and VIII