Auditory System Flashcards
What is the function of the thalamus? Where in the diencephalon is it found?
Relays most types of sensory information to neocortex; Dorsal (“roof”)
What is the function of the hypothalamus? Which part of the diencephalon is it found in?
Controls autonomic nervous system, controls motivated behaviors, controls many endocrine functions; Ventral (“basement”)
What is a part of the telencephalon?
Basal Ganglia, Limbic System, Cerebral Cortex
What does the Basal Ganglia control? What structures are in it?
Mediated motor, learning, and “reward” functions; Caudate/Putamen, Nucleus Accumbens
What is the limbic system? What is in it?
Mediates emotions, memory, and social behaviors; Medial Prefrontal Cortex, Hippocampus, Amygdala
What does the medial prefrontal cortex do?
Social behaviors, “working” memory, and other executive functions
What does the hippocampus do?
Learning & memory, stress
What does the amygdala do?
Aggressiveness, fear, anxiety, and other emotions
What are the lobes of the Cerebral cortex?
Frontal lobe, parietal lobe, temporal lobe, occipital lobe
What separates the 2 hemispheres? The frontal and parietal lobe? The temporal, frontal, and parietal lobe?
Longitudinal fissure; Central Fissure, Lateral Fissure
How many layers of cell bodies is there in the cerebral cortex?
6
What are the 3 properties of sound?
Frequency, Intensity, Complexity
What structures are found in the outer ear?
Pinna, Auditory canal, Tympanic Membrane
What structures are found in the middle ear?
Ossicles
What structures are found in the inner ear?
Oval window, Auditory vestibular nerve, Cochlea
What is the function of the attenuation reflex? How does it happen?
Adapt ear to loud sounds & improve speech perception; Onset of loud sound causes tensor tympani and stapedius muscle contraction
What is a general function of the ossicles?
Sound Amplification
What is the perilymph?
Fluid in scala vestibuli and scala tympani
What is the Endolymph?
Fluid in scala media
What is the job of the inner hair cells in the cochlea?
Providing auditory information that eventually reaches the brain
What is the job of the outer hair cells in the cochlea?
Regulate the “tightness” of the cochlea
Where are the stereocilia found in the cochlea? What do they do?
Contained at the top of each hair cell, extending into the tectorial membrane; Movement changes the polarization of hair cells
What does the Organ of Corti sit on?
Basement membrane
What is the process of transduction of sound pressure?
Sound pressure –> perilymph/endolymph movement –> basilar membrane movement –> stereocilia movement –> hyper or de polarize hair cells –> opening or closing of Ca channels –> incr. or decr. of NT release
What does movement of stereocilia towards long sterocilia mean? Short stereocilia?
Movement towards long stereocilia= depolairzation & open channels, short sterocilia= hyper polarization & closed channels
What 2 things determine sound intensity?
Firing frequency & Number of spiral ganglion neurons
What is place coding?
Different frequencies vibrate basilar membrane at different spots/places.
Low = apex High = Base
What is phase-lock coding?
Frequency of sound = frequency of action potentials locked on specific wave phase.
What 2 methods do we use to code for sound localization? At which frequencies do we use each?
Interaural time delay: Time taken for sound to reach each ear; Low frequencies
Interaural intensity difference: Intensity difference b/w the ears; Higher Frequencies
What is the central auditory pathway?
Hair cells –> Bipolar cells in the Spiral ganglion –> Vestibocochlear Nerve –> Ventral cochlear nucleus (brainstem) –> Superior olive –> Inferior Colliculus –> Thalmus - MGN –> Auditory cortex
