Auditory Pathway Flashcards
What carries information from organ corti to CNS?
Vestibulocochlear nerve
What are two auditory pathways?
Lemniscal- primary auditory cortex
Non-leminical- attention, suditory reflex
Where do spiral ganglions recieve info from?
Hair cells in organ of corti
Where do first order neurons synapse?
Ipsilateral cochlear nuclei
Where do ventral cochlear nerves bifurcate?
Where travel?
Ventral cochlear nucleus
- majority decussate contralateral superior olivary nuclei
- travel to contralateral lateral lemniscus
Minority ipsilateral lateral lemniscus
Where do all fibres arrive?
Inferior colliculus
Thalamus
Outline auditory pathway?
1) First order neurons in spinal ganglion recieve info from
hair cells in Organ of corti
2) Travel via vestibulocochlear nerve
3) Enter cranium through IAM
4) First order neuron synapse at cochlear nuclei
5) Fibres bifurcate- ventral and dorsal cochlear nucleus
6) Dorsal cochlear nucleus- most fibres denussate
6b) Some fibres remain ipsilateral
7) Fibres ascend lateral lemniscus
8) Arrive inferior colliculus
9) Project medial geniculate body in thalamus
How is auditory info conveyed- what nerve?
Vestibulocochlear
Which geniculate does auditory info pass through?
Medial geniculate body
music goes to medial and light goes to lateral
Which geniculate does vision info pass through?
Lateral geniculate body
music goes to medial and light goes to lateral
How is the primary auditory cortex organised?
Tonotopically
Outline how humans hear?
Outer ear
1) Sound occurs
2) Enters outer ear (pinna/auricle)
3) Sound hits pinna- amplify sound waves
4) Travel along ear canal
5) Sound waves hit tympanic membrane
Middle ear
6) Tympanic membrane vibrates
7) Ossicle vibrate (Malleus, incus, stapes vibrate)
8) Vibration push oval window
Inner ear
9) Pressure waves in cochlear
10) Organ corti- vibrations transformed into electrical energy by stereocilia
Label?
What is order of stapes?
Malleus
Incus
Stapes
What bone attached to tympanic membrane?
Malleus
