Week 3 midterm 2 Flashcards
What 2 functions is the ear specialized for?
- hearing
2. equilibrium
What is the visible part of the ear?
the pinna
What occurs in the middle ear? (primary function)
the amplification of sound waves in preparation for transmission from air to a fluid environment
Whats another words for the ear canal and what does it do?
the external auditory meatus - brings waves to the tympanic membrane
What is the primary function of the external ear?
to gather sound waves and conduct them to the tympanic membrane
What is the middle ear composed of (x4)?
- tympanic membrane (ear drum)
- ossicles (malleus, incus and stapes)
- oval window
- round window
What is the primary function of the inner ear?
the transduction/conversion of sound energy (fluid filled)
What is the inner ear composed of? (X2)
cochlea and vestibular apparatus
What is the external ear composed of?
ear canal (aka external auditory meatus) and pinna
What does the Eustachian tube do?
aka auditory tube, it connects the airfield middle ear with the pharynx (throat) to equilibrate pressure. Normally collapsed however it opens transiently to equilibrate middle ear pressure with atmospheric air
Malleus
aka hammer, first auditory ossicle
Incus
aka anvil, middle/second auditory ossicle
Stapes
aka stirrup, last/third auditory ossicle
What is the cochlea?
a coiled, bony, fluid filled tube in the inner ear through which sound waves trigger nerve impulses
What is the vestibular apparatus?
the receptive organs of the inner ear that contribute to balance and perception of head movement
How do sound waves work?
Don’t move from original position, they bump into adjacent molecules and transfer E which is transmitted in waves that radiate away from vibrating object (like ripples)
How do sound waves spread?
in 3 dimensions in a spherical way
What is amplitude?
intensity/loudness of sound (dB)
What is pitch?
frequency of waves/second (Hz)
What is pitch?
frequency of waves/second (Hz)
- low frequency = low pitch, vv
What exactly is sound?
the brains interpretation of the frequency, amplitude and duration of sound waves that reach the ears
What are infrasound waves?
sound waves with a frequency too low for the human ear to hear (whales, elephants and hippos) – can cause headaches and many other conditions when exposed to them for long periods of time
What are ultrasound waves?
Sound waves with a frequency too high for the human ear to hear (dogs, bats, insects and birds)
What happens when sound waves strike the tympanic membrane?
the membrane vibrates at the same frequency as the sound, which causes movement of ossicles (amplify sound waves) which then cause movement of the oval window (smaller than TM)
- mechanical vibrations from ossicles and oval window are converted into fluid waves