BSCI 201 Lecture Notes - Lecture 36: Frontal Lobe, Olfactory Tract, Mammillary Body
12 Dec 2016
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Document Summary
Pathway taken by sound waves in the external ear: Sound waves go to external auditory canal and then hit the tympanic membrane. Tympanic membrane then vibrates, and the vibrations are transferred to the. Malleus to the incus to the stapes. When the stapes vibrates, the vibrations are transferred to the perilymph in the bony labyrinth, which is made up of the vestibule, semicircular canals, and the cochlea. When the perilymph in the cochlea moves, the cochlear duct moves, and the endolymph moves as well as the organ of corti oscillates. If electrical signal is strong enough to initiate an action potential, then this action potential will travel via the vestibulocochlear nerve into the brain. In the brain, it will go to the medial geniculate nucleus (mgn), which is an auditory relay center of the thalamus. If auditory reflexes are involved, such as the startle reflex, then some of the impulse travels to the inferior colliculi in the midbrain.
