Hearing and Balance Flashcards
stagocyst (invertebrates)
sensory organ that contains ciliated receptor cells that respond to mechanical deformation
gives animal an indication of orientation in space
insect hearing
hairs on body that vibrate at different frequencies
tympanic membranes
tympanic membrane
air filled chamber. when struck it vibrates activating receptor cells which then signal to the brain
mammalian hearing
perception of the energy carried in sound waves
pitch and frequency
20-20,000Hz
most acute 1000-3000Hz
loudness
measured in decibels (dB)
conversation = 60dB
functional parts of the ear
external ear (pinna)
middle ear
inner ear
external ear (pinna)
acts as a reflector to capture sound efficiently and focus it toward the ear cannal
middle ear
air filled pouch extending form the pharynx, to which is is connected by the eustachian tube
beings at eardrum
contains 3 bones: ossicles: malleus, incus, and stapes
3 bones
ossicles: malleus, incus, and stapes
order of middle ear
tympanic membrane-malleus-incus-stapes- oval window
inner ear
vibrations transmitted from the stapes to the oval window cause fluid movements within the chambers in the cochlea
waves travel through and back to tympanic canal where pressure dissipates. as waves travel the organ of corti vibrate at the same frequency as the incoming sound.
Organ of Corti
vibrations cause the basilar membrane to vibrate and this pushes the hair cells against the tectorial membrane causing them to bend.
info is them carried out of the ear from the auditory nerve to the brain.
semicircular canals
3 distinct planes to detect angular head movements
ampula
contains hair cells (receptor cells)
cupula
as the head moves, endolymph moves, pushing on the cupula and bending the hair cells
Otolith Organs
sense linear acceleration and head position
contains patch of hair cells called macula
utricle and saccule
calcium carbonate crystals (otoconia) move with head position
in semicircular canals
utricle
30,000 hair cells
horizontal movements
saccule
16,000 hair cells
vertical movements
otoconia
calcium carbonate crystals, move with head position
subject to gravity
how are high frequency pitches detected
basilar membrane