Auditory System - 4/22 Stephens Flashcards
Where does the LL terminate?
From there where do the fibers project to? Via what?
Inferior colliculus
Medial geniculate body via the brachium of the inferior colliculus
Fibers from the medial geniculate body project to where?
Primary auditory cortex via auditory radiations
As ventral stira cross the ____, they form the ______.
These fibers terminate bilaterally in the ______. The _____ projects fibers to the inferior colliculus primarily through the ipsilateral _________.
ML, trapezoid body
Superior olivary nucleus (SON)
SON
LL
What directly links the auditory association area to Broca’s speech area in the frontal lobe?
Superior longitudinal fasciculus (arcuate fasciculus)
What plays a role in modifying auditory information?
Superior Olivary Nuclear Complex
What is the medial superior olivary nucleus important for?
Localizing sounds
What gives rise to most of the olivocochlear efferents?
Fx?
Neurons in the lateral superior olivary nucleus
Exert inhibitory influences upon the organ of Corti
How do fibers from the lateral superior olivary nucleus pass through the vestibular division and cross over to the cochlear division?
Vestibulocochlear anastomsis of Cort
Unilateral lesion of the cochlear nerve results in what?
Ipsilateral complete deafness
Unilateral lesion of the central auditory pathway results in what?
What structures are included?
Bilateral diminution of hearing, more prominent in contralateral ear
LL
Inf. Colliculus and brachium
MGB
Lesion of what results in conduction aphasia?
Characterized how?
What also may be present?
Arcuate fasciculus
Severe anomia, severe impairment of repetition, cannot read aloud
Right hemiparesis and hemianopia, orofacial and bilateral limb apraxia
Lesions of what structure result in auditory agnosia?
Characterized by what?
Auditory association cortex (POT)
Inability to comprehend auditory info
Wernicke’s aphasia characterized by what?
Damage to where?
Describe patients’ speech:
Receptive aphasia, inability to comprehend spoken or written word
Wernicke’s area (22) in dominant hemisphere
Word substitutions
Where is the nucleus of the trapezoid body located?
Important for what?
Junction of the ML and ventral acoustic stria
Central processing of auditory information
The dorsal and intermediate acoustic striae decussate where?
Ascend where?
Upper medulla
Contralateral lateral lemniscus (LL)
