SPLH 620 Unit 2 Study Guide with Complete Solutions(RATED A+)
3 views 0 purchase
Module
SPLH 620
Institution
SPLH 620
CN VIII: Vestibulocochlear - ANSWER-hearing and balance
- vestibular division
- cochlear division
- hearing and balance are functionally very different senses but begin similarly peripherally
-vestibular: position and movement of head
anatomy of hearing and balance - ANSWER-• Outer ear...
SPLH 620 Unit 2 Study Guide 2023-2024 with Complete Solutions(RATED A+)
CN VIII: Vestibulocochlear - ANSWER-hearing and balance - vestibular division - cochlear division - hearing and balance are functionally very different senses but begin similarly peripherally -vestibular: position and movement of head
anatomy of hearing and balance - ANSWER-• Outer ear - Pinna - Ear canal • Middle ear - Tympanic membrane - Ossicles (malleus, incus, stapes) • Inner ear - Cochlea - Vestibular system
middle ear - ANSWER-- Tympanic membrane - Air filled - Ossicles (Malleus, incus, stapes) - Oval Window
inner ear (cochlea) - ANSWER-fluid filled
middle ear function - ANSWER-•Amplification of signal •Transforms signal
•(acoustic->mechanical)
inner ear function - ANSWER-•Transforms signal: •Mechanical -> chemoelectric •Represent sound frequencies
How is sound transmitted? - ANSWER-Vibrations transmitted through the tympanic membrane, middle ear ossicles, and oval window reach the perilymph (fluid) of the inner
ear
cochlea - ANSWER-- a coiled tube (2.5 turns) with three chambers: • Scala vestibuli (perilymph)
• Scala tympani (perilymph) • Scala media (endolymph)
organ of corti - ANSWER-a stirp of hair cells that rest on the basilar membrane, that are within the cochlear membrane - wave energy from the cochlea causes the basilar membrane to vibrate, bending hair cells, generating action potentials
ear hair cells - ANSWER-- inner hair cells
- outer hair cells
- 90-95% of all cochlear nerve fiber receives input from IHC
-OHC amplify signal
tonotopic organization - ANSWER-an arrangement in which neurons that respond to different frequencies are organized anatomically in order of frequency
- high frequency sounds at the BASE
- low frequency sounds at the APEX
auditory pathway - ANSWER-1. Sound enters ear and stimulates the Auditory Nerve (CN VIII) 2. Information is passed through the Superior Olive, Lateral Lemniscus, Inferior Colliculus and Thalamus(medialgeniculatenucleusofthethalamus) (MGN) • Spatial hearing computed by interaural level / time differences 3. Auditory Cortex receives Thalamic input and processes signal - Tonotopic map is preserved in cortex
auditory pathway components - ANSWER-• Hair cells --> dorsal and ventral cochlear nuclei • Dorsal cochlear nucleus --> most axons cross over to inferior colliculus • Ventral nucleus --> axons synapse on the ipsilateral and contralateral superior olivary nucleus
auditory pathway components continued - ANSWER-• Lateral lemniscus - a large fiber bundle of the ipsilateral and contralateral ventral and dorsal axons • synapses in the inferior colliculus and goes on to the medial geniculate nucleus of the thalamus • From there to the temporal lobe of the auditory cortex • Each hemisphere receives info from both ears
Anatomy of Auditory Pathways - ANSWER--Afferents from spiral ganglion cells enter brainstem in the auditory vestibular nerve via 8th nerve at medulla
-Innervate both ipsilateral dorsal and ventral cochlear nuclei
-Cells in the ventral cochlear nucleus send out axons that project to the superior olive (superior olivary nucleus) on both sides of the brainstem
-Axons of the olivary neurons ascend via lateral lemniscus and innervate the inferior colliculus (IC) in the midbrain
-Inferior colliculus sends axons to the MGN
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller papersbyjol. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £9.31. You're not tied to anything after your purchase.
