Auditory Pathway Flashcards
Where is the auditory apparatus located?
Petrous part of temporal bone
why is the middle ear a high risk space?
1) connected to nasopharynx (prone to infection)
2) Connected to mastoid air cells (infection can spread to middle cranial fossa)
3) Internal jugular vein lies inferior (thrombosis risk)
4) Internal carotid artery lies anterior (link to pulsatile tinnitus)
5) Traversed by chorda tympani and facial canal (infection risk of nerves)
What contains perilymph / endolymph?
Perilymph lies in the cochlea.
Endolymph lies within the cochlear duct
Where to the cell bodies of the primary auditory fibres lie?
Spiral Ganglion
What are the auditory centres in the brain (start caudally and go up)
1) Cochlear nuclei (most caudal)
2) Superior olivary nucleus
3) Inferior colliculus
4) Medial geniculate nucleus of thalamus
5) Heschl’s gyrus
What auditory centres lie in the pons, midbrain, thalamus and cerebral cortex?
Pons = Superior olivary nucleus
Midbrain = Inferior colliculus
Thalamus = Medial Geniculate Nucleus
Cerebral Cortex = Heschl’s Gyrus
In what tract does the auditory information run between the superior olivary nucleus and the inferior colliculus?
Lateral Lemniscus
In what tract does the auditory info run between the inferior colliculus and the medial geniculate nucleus?
Inferior Brachium
What area of heschl’s gyrus responds to Low pitch?
AnteroLateral part of Heschl’s gyrus.
Where is broca’s area and what is it’s function?
Lies anteriorly.
Function : production of words
Where is wernicke’s area and what is its function?
Lies posteriorly
Function : understanding
What artery supplies brocas and wernickes area?
Middle cerebral artery
What causes deafness?
1) conductive deafness (defect of sound transmission to spiral ganglion)
2) Sensorineural deafness (defect in function of spiral ganglion or cochlear nerve)
Which hearing test bypassed amplification structures? (ie. oscicles)
Weber’s test
What test is used to determine unilateral hearing loss?
Weber’s test
