A & P 2 Exam 1: Hearing Flashcards
otitis media
inflammation of the middle ear
ear infection
common in kids because their ear is so small it is easy to get up there
internal ear/labyrinth
2 divisions: bony labyrinth and membranous labyrinth
bony labyrinth
cavity in temporal bone with: semicircular canals, vestibule, cochlea
membranous labyrinth
ducts and sacs: semicircular ducts, utricle, saccule, cochlear duct
what is the fluid in the bony labyrinth
perilymph
what is the fluid in the membranous labyrinth
endolymph
cochlea
contains sensory receptors for hearing
what parts are involved in equilibrium
vestibule and semicircular canals
what is a soft wormlike tube that winds thorugh the full turns of the cochlea and separates the perilymph cochlea cavity into upper nd lower chambers (scala vestibuli and scala tympani)
cochlear duct
where does the scala vestibuli terminate
the oval window which seats the foot plate of the stapes
the scala tympani is bound by a membranous area called the—–
round window
what contains the receptors for hearing
spiral organ
what forms the floor of the cochlear duct
basilar membrane
roof of the cochlear duct is called the
vestibular membrane
mechanism of hearing
vibration of stapes at oval window creates pressure waves in perilymph of scala vestibuli which are transferred to endolymph in the cochlear duct
basilar membrane is displaced by pressure waves and the hairs bend - depolarization occurs from bending of hair cells
results from damage to neural structures anywhere from the cochkear hair cells through neurons of the auditory cortex
sensorineural deafness
acuity test
- pack an ear with cotton
- obtain ticking clock hold it close to unpacked ear and then walk away, measure distance wen they stop hearing ticking
weber test
to determine conduction and sensorineural deafness
- tuning fork on persons head, is it heard equally on both sides
occurs when something prevents sound waves from reaching the fluids of the internal ear
- ear wax, inflammation, damages ossicles can be causes
conduction deafness
rine test
used to compare bone and air-conduction hearing
- srike tuning fork and place on mastoid process
- when no longer hear sound hold close to external accoustic meatus
if they hear it again hearing is not impaired,
bone conduction: put on mastoid process first
air conduction: put near external accoustic meatus first
what dos the vestibule contain
utricle and saccule
what does the semicircular chambers contain?
semicircular ducts
what do semicircular canals monitor?
rotational acceleration
- dynamic equilibrium
3 planes - frontal, horizontal, sagittal
within each ampulla is a ______ which consists of a tuft of hai cells covered by a ___
crista ampullaris ampullay cupula (gelatinous cap)
how does the endolymph move?
it lags behind the actual movement
contains another set of hair cells that monitor head position and acceleration in a straight line?
- static equilibrium
maculae
gelatinous material containing small grains of calcium carbonate called (otolith)
otolith membrane
nystagmus
involuntary rolling of the eyes in any direction or the trailing of eyes slowly in one direction followed by rapid movement of eyes in oppposite direction
barany test
nystagmus and verigo testing
- evaluates semicircular canals
if semiciruclar canals normal: get sensation the stool is still rotating immediately after it has stopped - nystagmus demonstrated
when sunject rotated to the right, ampullary cupula bent to the left cusing nystagmus
romberg test
detemines integrity of dorsal white column of spinal cord
proprioception, posture
