All flashcards
Flashcard 1: What is the organ of Corti?
Answer: Sensory epithelium containing hair cells on the basilar membrane. Contains inner and outer hair cells that transduce sound.
Flashcard 2: Which cue is primarily used for localizing low-frequency sounds: ITD or ILD?
Answer: Interaural time difference (ITD). Low frequencies reach ears at slightly different times based on source location.
Flashcard 3: What is tonotopic organization in the auditory system?
Answer: Systematic mapping of sound frequency across cochlea and auditory cortex. Preserves frequency information spatially throughout auditory pathway.
Flashcard 4: Which cochlear region responds best to high-frequency sounds: base or apex?
Answer: Base of the cochlea. The stiff, narrow base resonates with high frequencies.
Flashcard 5: Which cochlear region responds best to low-frequency sounds: base or apex?
Answer: Apex of the cochlea. The wide, flexible apex resonates with low frequencies.
Flashcard 6: What is the difference between sensorineural hearing loss and conductive hearing loss?
Answer: Sensorineural: hair cells/nerve; Conductive: outer or middle ear conduction. Sensorineural affects neural transduction; conductive blocks sound transmission.
Flashcard 7: What is the difference between place theory and frequency theory of pitch perception?
Answer: Place: location on basilar membrane; Frequency: firing rate matches sound frequency. Place uses spatial coding; frequency uses temporal coding of pitch.
Flashcard 8: What is the correct path of sound conduction from outer ear to cochlear receptors?
Answer: Pinna → ear canal → tympanic membrane → ossicles → oval window → cochlea. Sound travels through outer, middle, then inner ear structures sequentially.
Flashcard 9: What is the primary function of the pinna (auricle) in hearing?
Answer: Collects and localizes sound; funnels sound into the auditory canal. The outer ear structure helps determine sound direction and amplifies certain frequencies.
Flashcard 10: What is the primary function of the tympanic membrane in hearing?
Answer: Converts air pressure waves into mechanical vibrations. The eardrum vibrates in response to sound waves, initiating mechanical transduction.
Flashcard 11: Which three middle-ear bones (ossicles) transmit vibrations to the inner ear?
Answer: Malleus, incus, stapes. These tiny bones amplify and transmit vibrations from eardrum to inner ear.
Flashcard 12: What is the specific role of the stapes at the oval window?
Answer: Transmits ossicle vibrations into cochlear fluid via the oval window. The footplate pushes fluid in the cochlea, converting mechanical to fluid waves.
Flashcard 13: What is the organ of Corti, and where is it located?
Answer: Hair-cell sensory organ on the basilar membrane within the cochlea. Contains the actual hair cells that transduce sound into neural impulses.
Flashcard 14: Which cochlear structure contains the sensory hair cells for hearing?
Answer: Organ of Corti. Contains inner and outer hair cells that transduce sound.
Flashcard 15: What is the immediate stimulus that bends cochlear stereocilia during sound transduction?
Answer: Shearing between tectorial membrane and basilar membrane. Relative motion deflects hair cell bundles.
Flashcard 16: Which basilar membrane region responds best to low-frequency sounds?
Answer: Apex of cochlea (near helicotrema). More flexible basilar membrane vibrates best at low frequencies.
Flashcard 17: What is the function of the oval window in the auditory system?
Answer: Transmits stapes vibrations into cochlear fluid. The stapes footplate pushes here to create fluid waves.
Flashcard 18: What is the key mechanical role of the ossicles in hearing?
Answer: Impedance matching; amplifies pressure at the oval window. Converts air vibrations to fluid vibrations efficiently.
Flashcard 19: What are the three auditory ossicles in the correct anatomical order?
Answer: Malleus → incus → stapes. The hammer, anvil, and stirrup transmit vibrations sequentially.
Flashcard 20: Which cue primarily supports sound localization in the horizontal plane for high frequencies?
Answer: Interaural level (intensity) difference (ILD). Head shadow creates loudness differences between ears.
Flashcard 21: Which two binaural cues are used for sound localization in the horizontal plane?
Answer: Interaural time difference and interaural level (intensity) difference. Brain compares arrival time and loudness differences between ears.
Flashcard 22: What is the primary auditory cortex, and where is it located?
Answer: A1 in the temporal lobe (superior temporal gyrus). First cortical area for conscious sound processing.
Flashcard 23: Which pitch theory best explains high-frequency sounds, and what is its core idea?
Answer: Place theory; pitch depends on maximal basilar membrane displacement location. Different frequencies peak at different basilar membrane locations.
Flashcard 24: Which pitch theory best explains low-frequency sounds, and what is its core idea?
Answer: Frequency theory; auditory nerve firing rate tracks sound frequency. Neural firing synchronizes with low-frequency sound waves.
Flashcard 25: What is the volley principle in auditory coding?
Answer: Groups of neurons alternate firing to represent higher frequencies. Overcomes single neuron firing rate limits for mid-range frequencies.
Flashcard 26: Which structure carries auditory information from the cochlea to the brainstem?
Answer: Cochlear nerve (auditory branch of cranial nerve VIII). Part of the vestibulocochlear nerve carrying auditory signals.
Flashcard 27: What is the immediate stimulus that opens mechanically gated channels in cochlear hair cells?
Answer: Deflection of stereocilia from basilar membrane vibration. Bending opens ion channels, depolarizing the hair cells.
Flashcard 28: What is the primary function of the Eustachian tube in auditory physiology?
Answer: Equalizes middle-ear pressure with atmospheric pressure. Prevents pressure buildup that would dampen eardrum movement.
Flashcard 29: What fluid-filled structure of the inner ear contains the sensory organ for hearing?
Answer: Cochlea. This spiral structure converts fluid waves into neural signals.
Flashcard 30: Identify the hearing loss type caused by damaged hair cells after chronic loud noise exposure.
Answer: Sensorineural hearing loss. Damage to cochlear hair cells or auditory nerve causes this type.