7: Auditory System Flashcards
1
Q
What is Sound Composed of?
A
- Acoustic waves
- It’s the vibration of air molecules at a high frequency (waves/ sec)
- Concentric waves = compression & rarefraction
2
Q
What’s the Function of the Eustachian Tube?
A
- Throat to middle ear passage
- For pressure equalization b/w outer & middle ear
- -Pressure = +/- pain/ difficulty w altitude
- Yawn/ swallowing = opens tube & relieves pressure
- Bulging in/ out of tympanic memb = pain/ pressure
- -Eustachian tube helps this!
3
Q
Explain the Attenuation Reflex Muscles.
A
Two Small Muscles: Tensor Tympani & Stapedius
- When they contract, they break vibration of ossicles
- -Reduces sensed vibration in ear
- -Contract when you talk! This way your voice isn’t too loud for you
- –Is a reflex loop
4
Q
How is Pressure Amplified in the Middle Ear?
A
Through 2 Mechanisms:
- The oval window is much smaller than the tympanic membrane, so equal force is funnelled to a smaller area, increasing pressure!
- Need higher pressure @ oval window to push fluid - The stapes displaces the oval window w about 1/10 displacement of the tympanic membrane, but much greater force!
- The ossicles are a lever system