equalises pressure in the middle and outer ear.
Eustachian tube
is the smallest bone in the body.
stapes or stirrup
absorbs extra pressure waves in the perilymph.
round window
contains receptors for hearing.
cochlea
contains sensory neurons.
auditory nerve
has receptors for perception of gravitational pull.
ampulla
State two functions of the ear. (2)
Hearing
Balance
Name the first structure to vibrate when sound enters the ear. (1)
Tympanic membrane
List the path followed by a sound wave/pressure wave, from the time it enters the ear until it strikes the round window. (6)
Pinna; auditory canal; tympanic membrane; ossicles; oval window; cochlea.
List the membranes that vibrate when sound is being transmitted in the ear. (3)
Tympanic membrane; oval window; round window
contains sensory neurons.
auditory nerve
Is the auditory nerve a sensory, motor or a mixed nerve? Explain. (3)
Sensory nerve. It carries impulses to the cerebrum only where the sound is perceived.
State the function of the Eustachian tube. (2)
Eustachian tube allows for the equalisation of pressure on either side of the tympanic membrane.
Explain what would happen if the Eustachian tube is blocked with mucus. (2)
Tympanic membranes /ossicles will not vibrate freely to transmit vibrations on the inner ear /cannot equalise pressure on either side of tympanic membrane. This will cause partial deafness.
