Auditory and Vestibular Pathways

Question 1

Where is the spiral ganglion and what does it do?

Answer 1

It is in the cochlea.

Has bipolar neurones which carry APs from organ of corti to cochlear nuclei in the pons

Question 2

What is the pathway of neurones from the cochlea to the brain?

Answer 2

Spiral ganglion -> Ventral cochlear nucleus -> Dorsal cochlear nucleus -> Superior olivary nucleus -> Inferior colliculus -> Medial geniculate nucleus in thalamus -> Auditory cortex

Question 3

What parts of the auditory pathway are important in sound localisation and as relays for stapedial and tensor tympani reflexes?

Answer 3

Superior olivary nucleus and nucleus of lateral lemnicus.

Question 4

Where in the auditory cortex is low frequency sound processed and where is high frequency sound processed?

Answer 4

Low frequency - anterolateral auditory cortex

High frequency - posteromedial auditory cortex

Question 5

Where are the 4 places that neurones from the vestibular nuclei go?

Answer 5

Thalamus
Cerebellum
Nuclei of CN III, IV, and VI (vestibuloocular reflex)
Spinal cord (vestibulospinal tracts)