Hearing Part 1 Flashcards
(24 cards)
What is the general pathway of the auditory system (ear pathway)?
outer ear –> inner ear –> mechanical force of sound transduced into neural activity (action potentials)
What is transduction?
Conversion of one form of energy to another
What are the sections of the external ear?
Pinna, ear canal
What are the sections of the middle ear?
tympanic membrane, ossicles, oval window
What are the sections of the inner ear?
Cochlea (subsections = scala vestibula, scala media (Organ of Corti), scala tympani)
What part of the ear captures, focuses, and filters sound?
External ear
What is the external part of the ear, ridges/valleys modify character of sound?
Pinna
What is the ear canal?
tube leading from pinna to tympanic membrane, sound waves funnel through
What part of the ear concentrates sound energies; collection of tiny membranes, muscles, and bones (little microphone) that links ear canal to inner ear
middle ear
What is the tympanic membrane (eardrum)?
partition between external ear and inner ear that vibrates with same frequency as sound
What are the ossicles?
three small bones (incus, malleus, stapes) that transmit and amplify vibration across the middle ear (from tympanic membrane to oval window) - like a chain of bones
What is the specialized patch of membrane that receives vibrations from the tympanic membrane through the ossicles
Oval window
What is the cochlea?
snail shaped structure in inner ear canal that contains primary receptor cells for hearing
What are the three channels in the cochlea?
Scala vestibuli (vestibular canal), scala media (middle canal) contains OoC, scala tympani
What is the Organ of Corti?
in scala media, converts vibrations from sound into neural activity; lies on basilar membrane of cochlea + contains hair cells and auditory nerve terminals
What are the hair cells of the OoC?
receptor cells of hearing, stereocilia on top, transduce vibrational nrg into neural activity
What are sterocilia?
tiny bristle (hair) that protrudes from a hair cell in the auditory/vestibular system
What is basilar membrane?
in OoC, contains principle structure for auditory transduction
What is the gelatinous membrane at top of OoC?
tectorial membrane
What is the pathway from the middle ear to inner ear?
tympanic membrane vibrates –> ossicles move –> vibrations transferred to oval window –> waves in liq of scala vestibuli and scala tympani –> basilar membrane ripples
What is the pathway for the ion channels in relation to auditory system?
basilar membrane ripples –> stereocilia bent –> mechanical ion channels open
(K+ enters –> depolarizes –> Ca+2 enters –> synaptic vesicles fuse –> ntrans released)
What are the roles of IHC and OHC?
inner/outer hair cells, contacted by axons from vestibulocochlear nerve (CN VIII)
What axons send info to the brain?
afferents
What axons bring info from the brain?
efferents