Case 4 - Auditory Pathway Flashcards
where do afferents from the spiral ganglion enter the brainstem in
the vestibulocochlear nerve
what happens at the level of the medulla
the axons innervate the dorsal cochlear nucleus and ventral cochlear nucleus ipsilateral to the cochlea where the axons originated
what do cells in the ventral cochlear nucleus do
send out axons that project to the superior olive on both sides of the brain stem.
where do axons of the olivary neurones go
the lateral leminiscus and innervate the inferior colliculus of the midbrain
many efferents of the dorsal cochlear nerve follow a route similar to the pathway from the ventral cochlear nucleus, but the dorsal path bypasses the superior olive
where do all ascending auditory pathways converge onto
the inferior collucilis
what do the neurones in the inferior colliculus send out
send out axons to the medial geniuculate nucleus or the thalamus, which in turn projects to the auditory cortex
what is the sensory pathway that carries peripheral sensation to the brain referred to as
the ascending pathway
where does the ascending pathway ascend through
three brainstem nuclei. begins by travelling along the VC nerve, which synapses with neurones in the cochlear nuclei of the superior medulla. the cochlear nucleus receives information from the cochlea. the inout received in the cochlear nucleus is only from one side of the bod y
what is the next part of the ascending process
the superior olivary nucleus. the SON takes information from the cochlear nucleus and beings the process of interpreting and combing information. this begins the process of sound localisation through estimating time difference and intensity between each ear
what happens after the superior olivary nucleus
auditory processing continues on to a nucleus called the inferior colliculus. the IC is a midbrain structure that integrates the vast majority of the ascending auditory information and projects via the thalamus to the auditory cortex. the IC Is also a point of convergence for corticofugal input and inout originating outside the auditory pathway
what does the medial geniculate nucleus of the thalamus then receive
the auditory information form the three brainstem nuclei. the information is integrated and the medial geniculate nucleus projects that information to the auditory cortex in the temporal lobe of the cerebral cortex.
