Lecture 16- The ear: hearing and balance Flashcards
what is hearing?
our brains perception of sound energy
what is sound transduction?
conversion of mechanical energy of sound waves to electrical energy
what is pitch?
our interpretation of frequency
what is loudness/ volume?
our perception of intensity/ amplitude of sound waves
what does the processing of sound tell us?
tells us about distance direction and movement
what are sound waves?
compressed air
what structures are in the external ear? 3
pinna: directs sound waves into the ear
external auditory canal
tympanic membrane
what structures are in the middle ear? 4
ossicles (malleus, incus, stapes)
eustachian tube (connects to pharynx/throat)
what structures are in the inner ear? 5
semicircular canals
vestibular apparatus
oval window
cochlea
nerves
what are the two different large overall structures of the inner ear?
bony labyrinth
membranous labyrinth
what is the difference between bony labyrinth and membraneous labyrinth?
membranous labyrinth is located within bony labyrinth
membranous labyrinth is filled with fluid
what does the membranous labyrinth contain?
cochlear duct with organ or corti
3 semicircular ducts with 1 crista ampullaris in each
utricle/saccule with 1 macula in each
what happens when you hear sounds? what is the process?
- sound waves strike the tympanic membrane and vibrates
- vibration is transferred to the 3 bones of the middle ear
- vibrations of the oval window create fluid waves within the cochlea
- fluid waves cause hair cells to bend and ion channels to open which causes neurotransmitter release
- neurotransmitter release onto sensory neurons creates AP that travel through cochlear nerve to brain
- energy from waves transfers across the cochlear duct into the tympanic duct, then brought back into middle ear at the round window
what is the process of hearing sounds through the cochlea in simple terms? Old Vegetables Help Tame Rabbits
oval window
vestibular duct
helicotrema (end of cochlea)
tympanic duct
round window
what does the cochlear nerve do?
transmits action potentials from the primary auditory neurons to cochlear nuclei in the medulla on their way to the sensory cortex