Audition (Hearing) Flashcards
Exam 2
Audition
Act, sense, or power of hearing sound
Sound
Series of pressure waves in air
Frequency; How is it measured?
of waves
Measured in Hertz (Hz) or Kilohertz (kHz)
# of waves
High pitch = _________ frequency
High
Intensity; How is it measured?
Amplitude/height of waves; Measured in decibels (dB)
Auricle
Pinna of ear; funnels soundwaves to inner ear
External auditory meatus
Connects auricle with eardrum; carries sound to eardrum
What substance does the external auditory meatus contain?
Cerumen (earwax)
Tympanic membrane
The eardrum; vibrates in response to sound waves
Middle ear is an air filled cavity with ________________
three bones
Oval window
Brings vibrations from ossicles to inner ear
Round window
Pushed out in response to inner ear waves
What are the three bones in the ear?
- Malleus (hammer)
- Incus (Anvil)
- Stapes (stirrup)
These bones vibrate when the ___________ moves
eardrum
Inner ear is filled with fluid or air?
Fluid
Cochlea
hearing; a long coiled tube; looks like a snail
What are the three channels in the cochlea
- top tube (Scala Vestibule)
- middle tube (Scala tympani)
- bottom tube (Scala media)
Scala vestibule
Connects to oval window
Scala tympani
Connects to round window
Scala media
Holds the organ of corti
Organ of Corti
Hair cells that change waves to electrical signals
Hair Cells
Sensory receptors for sound
Stereocilia
Stick out of top of cells
What connects stereocilia to other stereocilia?
Tip links
What type of gate channel is a tip link bound to?
Mechanical gated channels
Endolymph
Surrounds the hair cells
Perilymph
Surrounds the hair cell BODY
Endolymph has a ___________ K+ ECF, while perilymph has a ____________ K+ ECF
High; Low
Signal transduction
Changing waves to electrical impulses
Does K+ enter or leave the cell through the mechanically gated tip links?
Enter
Do hair cells send action potentials?
NO, only graded potentials
Does K+ depolarize or repolarize the cell?
It does both!
K+ entering the cell body depolarizes cell, opening the ____________
Voltage-gated Ca2+ channels
The Intracellular calcium stimulates and releases what NT?
Excitatory glutamate
K+ enters the cell from the endolymph because it is _______ in the ECF
High
K+ exits the cell into the perilymph because of the ______________
Concentration gradient; high ICF concentration
High pitch = _______ frequency
High
Increasing the intensity means we increase the __________ of waves
amplitude
Apex is _______ & ________
Thick and floppy
Base is _________ & ___________
Thin and stiff
Base is for _____ frequencies
High
Apex is for ______ frequencies
Low
The activation of the basilar membrane depends on the ____________________
different frequencies in use
Trigeminal Ganglion
Cell bodies of neurons for head/neck/mouth
Bilateral integration is important for ____________________________
Sound localization
The pathway from the auditory nerve to the temporal lobe in brain (6)
- Same side ventral cochlear nucleus
- Bilateral superior olivary complex
- Lateral lemniscus
- Inferior colliculus
- Medial geniculate body
- Superior temporal gyrus
What part of the brain is the MGN located in?
Thalamus
What part of the brain is the Superior temporal gyrus in?
Temporal lobe
How is the A1 organized?
tonotopically; There are special spaces for different frequencies
