Lec 9 Auditory and vestibular systems

Question 1

amplitude

Answer 1

maximun displacement of the vibrating particle of the gievn medium from the mean position (height of wavelength from the middle)

Question 2

Wavelenght

Answer 2

distance between two corresponding points on adjacent waves (ie when it starts to repeat itself)

Question 3

Frequency

Answer 3

the number of cycles that pass a given point per second

Question 4

brief function of outer, middler and inner ear

Answer 4

o:collects sound, m:amplifies sound pressure, i: convert sound waves into nerve impuleses and involved in balance

Question 5

Tympanic membrane

Answer 5

Approx 8-10mm in diametre. vibrates in response to changes in air pressure in auditory canal (converts acoustic energy into mechanical energy)

Question 6

Ossicles

Answer 6

bones in middle ear, malleus(hammer), incus(anvil), stapes(stirrup). convert sound energy into mechanical energy and transfer to inner ear. also protect ear from damage from loud noises

Question 7

structure of cochlea

Answer 7

3 chambers separated by 2 membranes. scala media (cochlear duct), scala vestibule, scala tympani

Question 8

Organ of corti (in cochlea)

Answer 8

rests on the basilar membrane - it houses mechanoreceptors (hair cells) that convert sound/pressure waves into electrical signals

Question 9

Sound frequency is coded by…

Answer 9

the location on the basilar membrane where the action potentials are generated

Question 10

sound intensity is coded by…

Answer 10

the number of action potentials that are generated

Question 11

tonotopic organisation

Answer 11

the mapping of specific pitches/frequencies to specific areas (of the brain)

Question 12

Vestibular system: what it is and what its comprised of

Answer 12

a sensory system that contributes to the sense of balance and spatial orientation. (within the inner ear) comprises the semicircular canals and the otolith organs. they detect head motion and position

Question 13

semicircular canals

Answer 13

one end - swelling (ampulla) which contains a cone shaped structure (crista ampullaris) which contains several thousand motion receptors (hair cells)