Auditory pathway lecture Flashcards
Where is the auditory pathway located?
The petrous part of the temporal bone
Which nerves pass through the internal acoustic meatus?
vestibular cochlea and facial nerve
What are the three bones of the ossicles?
Incus
Malleus
Stapes
What is the function of the auditory tube?
Allows air to pass into the middle ear to maintain equilibrium - equalises pressure either side of the tympanic membrane
Where is the inner ear located?
In the pectoris part of the temporal bone
Which window do the ossicles hit?
The oval window
What are the cavities in the petrous part of temporal bone?
Vestibule
SSC
Cochlea
What is the fluid inside the cochlea?
Perilymph
What is the constituency of perilymph?
High in sodium
Low in potassium
(creates electrical potential)
What is the cochlear duct?
Membranous sack which runs through the cochlea
What type of fluid does the cochlear duct contain?
Endolymph
What two chambers does the cochlear duct separate the cochlea into?
The scala vestibuli
The scala tympani
What is the apex of the cochlea called?
Helicotrema
What forms the roof of the cochlear duct?
The Vestibular membrane
What forms the floor of the cochlear duct?
The basement membrane
What is the auditory receptor?
Spiral organ of corti - on the basilar membrane
How is the spiral organ stimulated?
by the deformation of the cochlear duct - due to the perilymph in the surround st and sv
Where does the vestibular cochlear nerve enter the brainstem?
Cerebellar pontine angle
Breakdown of auditory pathway?
Cochlea Spiral ganglion Cochlea nuclei Superior olivary nucleus Inferior calculus Medial geniculate nucleus Herschel's gyrus
Where is the superior olivary nucleus?
pons
Where is the inferior calliculus?
Midbrain
Where is the medial geniculate nucleus?
thalamus
Where is heschl’s Gyrus?
Temporal lobe - superior temporal gyrus
What tract is the nerve running in between superior olivary nucleus and inferior calliculus?
Lateral lemniscus
What tract is the nerve running in between inferior calliculus and medial geniculate nucleus?
The inferior brachium
Which end of basement membrane receives high pitch?
The proximal end
Which end of basement membrane receive low pitch?
The apex
What is the function of the secondary auditory areas?
Specialised linguistic function
What is broca’s area?
Understanding of words you are speaking - fluent speech
What is Werner’s area?
Understanding of spoken word
