Auditory Tracts Flashcards
Where do the primary afferents from the cochlear division of CN VIII enter the brainstem?
Pontomedullary junction
What is the function of the dorsal cochlear nuclei?
Identifying sound source elevation
What is the function of the ventral cochlear nucleus?
Horizontal localization of sound
What are the points of synapse in the monaural tracts?
Inferior colliculus
Medial geniculate nucleus
Layer IV of primary auditory cortex
Where does the monaural tract cross to the contralateral side?
Pons
Via dorsal acoustic stria
Fibers from the monaural tract travel through what part of the internal capsule to reach the medial geniculate nucleus?
Sublenticular limb of the internal capsule
What are the points of synapse of the binaural tract?
Superior olivary complex
Inferior Colliculus
Medial geniculate nucleus
Layer IV of primary auditory cortex
What structures do the binaural fibers cross in before ascending through the lateral lemniscus?
Trapezoid body in the pons
What is the blood supply to the auditory nuclei of pons and medulla?
Basilar A.
Occlusion of what branch of basilar A. will cause monaural hearing loss?
AICA
What is the blood supply to superior olivary complex and lateral lemniscus?
Short circumferential branches of basilar A.
What is the blood supply to the inferior colliculus?
Superior cerebellar A.
Quadrigeminal As.
What is the blood supply to the primary auditory and association cortices?
M2 segment of MCA
What is the function of the area analogous to Wernicke’s area?
Interpreting nonverbal signs from other people
What is the function of the area analagous to Broca’s area?
Instructions for producing non-verbal communication (i.e. emotional gestures and intonation of speech)
What fibers connect Wernicke’s and Broca’s areas?
Arcuate fibers (allow verbal repetition)
The inability to describe a sound that has been heard is known as what?
Auditory Agnosia
What has been damaged in auditory agnosia?
Bilateral temporal cortex in the sensory association cortex
Receptive aphasia is a defect in what area? What is lost?
Wernicke’s area
Unable to comprehend language in any form, cannot write or read (can still speak)
Expressive aphasia is a defect in what area? What is lost?
Broca’s area
Loss of ability to speak fluently (can understand spoken and written language)
What disorder would you see a patient using telegraphic speech?
Expressive Aphasia (Broca’s aphasia)
Occlusion of what artery can cause global aphasia? What areas have been damaged?
MCA
Broca’s and Wernicke’s areas
Where is the lesion in conduction aphasia?
Supramarginal gyrus and arcuate fasciculus
A patient is able to tell you his history and read and write normally. He is able to converse, however he is unable to repeat words you say to him. What type of aphasia is this?
Conduction aphasia
What area has been damaged in transcortical motor aphasia?
ACA-MCA border zone infarction
What area has been damaged in a transcortical sensory aphasia?
MCA-PCA border zone
What are the nonfluent aphasias?
Broca’s
Transcortical motor
Repetition is preserved in what aphasic syndromes?
Transcortical motor
Transcortical sensory
Which transcortical aphasia presents similar to Broca’s area?
Transcortical motor aphasia
Which transcortical aphasia presents similar to Wernicke’s aphasia?
Transcortical Sensory Aphasia
What is anomic aphasia?
Word finding difficulties
