Unit 2_Auditory Flashcards
What is created by molecular vibration which produces sound waves?
Sound
What property of sound includes the following:
Speed of vibration
- # of complete wave cycles per second (Hz)
- Determines pitch
- 20-20,000 Hz
Frequency
What property of sound includes the following:
- Amplitude of sound waves
- Measured in decibels (dB)
- Correlated with perceived loudness
->intensity to hear a low freq. sound than a high frequency sound (there is not a 1-1 relationship between loudness and intensity because the human ear is not equally sensitive to all sound frequencies) - Intensity range = 0-120 dB
Intensity
What structure of the ear includes the following:
External auditory meatus
Tympanic membrane (TM) separates external ear from middle ear
Functions to collect sound waves
Serves as resonator
External ear
What structure of the ear includes the following:
Air-filled cavity between inner ear and tympanic membrane (TM)
Malleus, Incus, Stapes-transmit vibrations to inner ear
Stapes contacts oval window
Malleus contacts TM
Stapedius muscle contacts stapes & tensor tympani contacts malleus to dampen sound
Eustachian tube joins the middle ear to pharynx-adjusts pressure in middle ear to atmospheric pressure
Middle Ear
What structure of the ear includes the following:
- Allow effective transmission of sound to inner ear
- Reflexively (muscles) control movements of ossicles during loud noises
- Adjust for changes in pressure
Middle Ear
What structure of the ear includes the following:
Dual Functioning Mechanism
- Audition (Hearing)
- Equilibrium (Vestibular)
Inner Ear
What component of the inner ear includes the following:
Interconnected canals and cavities
Petrous portion of temporal bone
Contains membranous labyrinth
Bony Labyrinth
What component of the inner ear includes the following:
Fluid filled cochlea
Coiled system of ducts
Scala media or cochlear duct – (endolymph)
Scala tympani - round window – (perilymph)
Scala vestibuli - oval window – (perilymph)
Membranous Labyrinth
What kind of fluid does the coiled system of ducts (scala media or cochlear duct) contain?
endolymph
What kind of fluid does the coiled system of ducts is (Scala tympani) connected to the round window contain?
perilymph
What kind of fluid does the coiled system of ducts (Scala vestibuli) connected to the oval window contain?
perilymph
What pathway includes the goal to transform sound vibration to neural impulses which travel in CN VIII towards the CNS?
Scala media contains Organ of Corti which is sensory organ for hearing-contains sensory receptors and sits on the basilar membrane.
Hair cells are receptor cells that sit in the basilar membrane with hairs imbedded in the overlying tectorial membrane.
Hair cells innervated by peripheral processes of first order neurons in spiral ganglion.
Auditory Pathway
What is pushed upon by stapes to create waves within the scala vestibuli?
Oval window
What helps reduce the pressure in the scala tympani?
Round windows