aud pathways Flashcards
Where does CN VIII divide into acending and descending branches?
pontomedullary junction
ascending branch of CN VIII synapses where?
anterior ventral cochlear nucleus
descendng branch of CN VIII synapses where?
posterior ventral cochlear nucleus
dorsal cochlear nucleus
where is monaural information routed to?
contralateral side
what is the pathway of monaural tracts?
dorsal cochear nucleus to contralateral via doral acoustic stria to up the lateral lemniscus (nuclei of lateral lemniscus) to inferior colliculus to brachium of inferior colliculus to medial geniculate nucleus (synapse here)
where do cell bodies in medial geniculate nucleus synapse?
Layer IV of primary auditory cortex
Heschl’s gyrus
describe the pathway of binaural pathway
from ventral cochlear nuclei to trapezoid body to superior olivary complex (lateral and medial) to up the lateral lemniscus (nuclei) to inferior colliculus to up brachium of inferior colliculus to medial geniculate nucleus to layer IV primary auditory cortex
what is conduction deafness?
deficiy related to obstructed,altered sound through tempanic membrane or ossicle chao
what is sensorineural deafness?
damage to cochlea,cochlear VIII to cochlear nucei
what is central deafness?
damage to central pathways
where supplies blood to auditory nuclei of pons and medulla, cochea?
basilar a
what supplie blood to inner ear and cochlea?
labyrynthine from AICA
what happens if AICA is occluded?
monaural hearing loss
can also damage facial nerve, ipsilateral facial paralysis, inability to look to side of lesion
what supplies blood to superior olivary complex and lateral lemniscus?
short circumferental branches of basilar
what supplies blood to inferior colliculus?
superior cerebellar and quadrigeminal arteries?
what supplies blood to medial geniculate bodies?
thalamogeniculate arteries
what supplies blood to primary auditory and association cortices?
M2 branch of middle cerebral artery
what is the dominant hemisphere in most afults for language?
left
what is wernicke’s area for?
comprehension of spoken language
what is brocas area for?
instruction for language output
planning movements to make speech
providing grammatical function for words
what is the right hemisphere area that is like wernickes, used for?
interpreting nonverbal signals from other people
what is the right hemisphere area that is like brocas, used for?
instructions for making nonverbal communication including emotional gestures and intonation of speech
what is the pathway for language comprehension?
primary auditory cortex to auditory association cortex to wernickes area to subcortical connections to brocas area to oral and throat region of sensorimotor cortex
what does the primary auditory cortex do?
auditory discrimination
what does auditory association cortex do?
classification of sounds
what do the subcortical connections do?
link wernices and brocas area
what does oral and throat region of sensorimotor cortex do?
cortical output to speech muscles
what does arcuate fasciculus do?
word repetition
what is auditory agnosia?
inabilit to identify an object, even hough you can hear it
what causes auditory agnosia?
lesion is in temporal lobe
unimodal sensory association cortex bilaterally
what happens if your wernickes area is not working?
cant comprehend language
cant understand what is said to you
cant read
cant write comprehensibly
paraphasic speech
what happens if brocas area is lesioned?
cant speak fluently
cant understand spoken and written language
mutism if its severe enough
if its less severe, limited speech (Slow speaking, nonessential words omitted)
what is a global lesion, what happens?
lesion of lateral sulcus
receptive and expressive deficits
cant read or write
what is a transcortical lesion?
sensory or motor, can repeat
what is conduction aphasia?
lesion of supramarginal gyrus and arcuate fasciculus
cant repeat, but intact fluency
can comprehend language
word finding difficulties
intact readng, cant write
what is special about transcortical motor lesion?
are nonfluent, everything else is pretty much ok
ACA-MCA border infarc
what is special about transcortical sensory lesion?
cant comprehend or name, everything else is ok
MCA-PCA border infarc
what happens if you have sensorineural damage to eat?
ipsilateral deafness
what happens if you have central deafness?
not deaf because of crossing over, but hard to localize sound
