Auditory and Vestibular System Flashcards
The mechanical displacement of the cochlear hair cell stereocilia towards the kinocilium elicits what events?
1) Influx of K+ through membranes of cilia
2) Influx of Ca2+ through voltage-gated Ca2+ channels
A mechanical injury to the basilar membrane in the inner ear has occurred. The site of damage is in a region nearest to the oval window. This lesion will result in what?
A loss of hearing high frequencies
Motion of the endolymph in the semicircular canals when the head is held still will result in the perception of what?
Continued rotation
Which brain stem structure plays a major role in determining the direction from which a sound originates?
Superior olivary nucleus
Rotation in the horizontal plane is best detected by?
The horizontal semicircular canal
Rotation in the vertical plane falling backwards maximally activates?
The posterior semicircular canal
Rotation in the vertical plane falling forwards maximally activates?
The anterior semicircular canal
What detects linear acceleration forward and backward (running)?
Utricle
What detects linear acceleration up and down (jumping)?
Saccule
In the basilar membrane the one row of inner hair cells is?
Primary source of auditory information
In the basilar membrane the three rows of outer hair cells are?
Amplifiers so that inner hair cells have a stronger signal to send to the brain
Inner hair cells receive afferent innervation from the?
Spiral ganglia
Outer hair cells receive efferent innervation from?
Superior olivary complex
What row of hair cells detects otoacoustic emissions?
Outer hair cells
What happens when soundwaves hits stapes and cases it to move?
Scala vestibuli pressure falls below scala tympani pressure
Scala vestibuli pressure falling below scala tympani pressure causes?
Basilar membrane bowing upward
Depolarization of outer hair cells activates intracellular contractile proteins, which accentuates?
1) Upward movement of the basilar membrane
2) Makes waves in endolymph
Depolarization of inner hair cells causes?
Opening of voltage gated Ca2+ channels
What happens following deflection of the stereocilia?
K+ ions enter the cell and depolarize it
What does the scala media have in terms of charge?
A high positive charge
What maintains the electrochemical properties of the endolymph?
Stria vascularis
Decreased concentration of K+ in the endolymph compared to normal is seen when?
The stria vascularis is damaged
What integrates the acoustic information with somatosensory information?
Dorsal cochlear nuclei
What begins processing the temporal (time components) and spectral (tone) features of sound?
Ventral cochlear nuclei
The superior olivary complex receives what type of input?
Glutamatergic (excitatory)
The superior colliculus takes location data from the IC and adds what final dimension to create a spatial map of the sound’s location?
Vertical height
Information about time and intensity differences converse into where to help create a precise origin of sound location along the horizon?
Inferior colliculus
The inferior colliculus suppresses information related to what?
Echoes
What is a relay station in the auditory pathway and has lots of convergence form distinct spectral and temporal pathways, allowing for processing features of speech inflections?
Medial geniculate nucleus of the thalamus
What is essential in conscious perception of sound and the higher order processing of sound (loudness, modulations in volume, rate of frequency modulation)?
Primary auditory cortex (A1)
What area is thought to respond to more complex sounds such as music, naming a sound, and human speech?
Auditoyr (secondary) association cortex
Rostral areas of auditory cortexes are activated by?
Low frequencies
Caudal areas of auditory cortexes are activated by?
High frequencies
The hair cells in the oval window are best at detecting?
High frequency
The hair cells in the helicotrema are best at detecting?
Low frequency
If the frequency of vibration is near oval window, the basilar membrane is?
Narrow and stiff
If the frequency of vibration is near helicotrema, the basilar membrane is?
Wide and flexible
What ion channel on stereocilia tips are opened when the tip links joining the stereocilia are stretched?
TRPA1
Incoming Ca2+ from voltage gated calcium channels leads to the release of?
NT from synaptic vesicles
