Sensory disorders Flashcards
What is the ciliary muscle
tissues and muscles tha surround the lens of the eye
What are canals of Schlemm
tube shaped passage carrying air, liquids, or semisolid materials
What is the cornea
transparent convex membrane hat covers the pupil and iris
What is the pupil
dark circular opening at the center of the iris in he eye where light enters the eye
What is the lens
focuses light to produce an image on he light sensitie cells of the retina
What is the iris
colored part of the eye that consists of muscular diaphragm surrounding the pupil and regulating the light entering the eye by expanding and contracting the pupil
What is conjunctiva
delicate mucous membrane that covers the internal part of the eyelid and is attached to the cornea
What is the vitreous humor
fluid component of the gel that fills the main cavity of the eye b/t the lens and retina
What is the sclera
dense outer coating of the eyeball that forms the white of the eye
What is the retina
light sensitive membrane in the back of the eye containing rods and cones that receive an image from the lens and send it to the brain through the optic n
What is the choroid
brownish membrane b/t the retina and sclera that contain blood vessels nd large pigmented cells
What is the macula
small yellowish spot in the middle of the retia that provides the greatest visual acuity and color perception
What is the fovea
shallow pit in the center or the retina that is free of blood vessels and has the highest concentration of cells sensitive to color and bright light
what is considered legal blindness
20/200
What is ambulatory blindness
20/800
loss of visual acuity to the extent that vision can no longer guide ambulation
What are retinopathies
visual deficits resulting from primary or secondary retinal disease
What are the most common retinopathies
diabetic retinopathy prematurity hypertension atherosclerosis AIDS
Cause of retinopathies
Retinal detachment
Systemic (ischemia, hypoxia, infection, glaucoma)
Neo-vascularization (eye produces additional blood vessels leading to blood leaking in the eye)
What do retinopathies casue
Visual loss
visual acuity affecte
Prevention/tx of retinopathies
Tx underlying disease
edu
surgical repair or retina
laser surgery to destroy weakened blood vessels
What is glaucoma caused by
increase introcular pressure due to an excessive accumulation of aqueous humor
What does glaucoma cause damage to
optic n
What are the 2 causes of glaucoma
Vascular: increase pressure causes decreased blood flow
Mechanical:structures near optic n opening are affected caused increased pressure on the n axons
S&S of glaucoma
Gradual and subtle , harmful or destructive onset
loss of peripheral vision
profress to center of vision field
halo vision
mild eye pain which becomes intense
cornea bulges and is unresponsive to light
can lead to total blindness
Prevention for glaucoma
TX
Eye exams, edu
Meds,surgery
What are cataracts
progressive clouding of the lens
What causes cataracts
changes caused by degeneration related to aging or metabolic abnormalities
congenital cataracts-maternal infection
S&S of cataracts
Blurred vision which becomes darker over time
Tx for cataracts
surgery
What causes macular degeneration
genetic factors ad env exposure
S&S of macular degeneration
central vision becomes blurred then lost
depth perception affected
no pain and peripheral vision is not lost
TX for macular degeneration
laser and drug tx
What are the 2 types of macular degeneration
Wet: blood vessels leak blood and fluid into the macula
Dry: deterioration of macula (less severe)
OT for vision
Adpative things (enhance lighting, color code, magnifiers, talking books)
What is in the external ear
Auricle
External acoustic meatus
external auditory meatus
Eardrum
What is the auricle
part of the external ear tha tprojects outward from head
What is the external acoustic meatus
passage that controls and absorbs sound in the ear hat leads to the eardrum
What is the external auditory meatus
carries sound in the ear that leads to the eardrum
What is the eardrum
a membrane of thin skin and fibrous tissues that vibrates in response to sound waves
What is the eustachian tube
bony passage extending from the middle ear to the nasopharynx which has a role in equalizing air pressure on both sides of the eardrum
What are the ossicles
3 tiny bones
malleous
incus
stapes
What is the malleus (hammer)
outermost of the 3 small bones in the middle ear which transmits sound waves from the eardrum to the inner ear
What is the incus (anvil)
in the middle ear b/t the maleus and stapes bones
What is the stapes (stirrup)
innermost that transmitts vibration to the inner ear
What are semicircualr canals
any one of 3 tubes in the inner ear
semicircular in shape
set at right angles to one another that assist in maintaining balance
What is the vestibule
middle cavity of the inner ear b/t the cochlea and semicircular canals
What does the vestiule do
maintain balance and orientation by monitoring the sensations of movt and position
What is the utrculus
special sensory areas in the walls that send impulses to the brain indicating the position of the head
What is the sacculus
may aid in determining body orientation but may also have a function in hearing
What is the cochlea
spiral structure in ear w/ over 10,000 tin hair cells which move in response to sound waves
What is the cochlea divided into
3 fluid filled canals (vestibular, cochlear, tympanic canal)
What is the basilar membrane
partition b/t the cochlear canal and tympanic canal
What is the organ of corti
embedded in the basilar membrane
hairlike projections that receive sound vibrations from the middle ear and send them on to the brain via the auditory n. which are recognized and interpreted as specific sounds
What is loudness and intensity of a noise called
decibel
What number decibel is the softest audible to humans
0
What decibel is audible breathing
10
What decibel is soft whisper
20
What decibel is normal convo
60
What decibel is music in the car or a vacuum
70
What decibel is a concert
100-110
What decibel is painful
above 140
What decibel will rupture ear drums
150
What is tone
sound with a particular quality
What is pitch
sounds vibration frequency
What happens with a greater frequency
higher pitch
What does the max range of human hearing include in frequencies
15-18,000
The human ear cant hear what
very low frequencies
what is conduction deafness
sound is blocked in the external and middle ear
Tx for conduction deafness
hearing aids
What is sensorineural deafness
damage to the organ of Corti or auditory n.
What is tx for sensorineural deafness
cochlear implant
What is otis media
inflammation of infection of the middle ear
What causes otis media
allergies
infection
(more common in kids in winter months)
S&S for otis media
asymptomatic usually ear pain tympanic membrane is red and bulging fever nausea
TX for otis media
antibiotics
decongestants
tubes
What are the functions of the vestibular system
maintain equilibrium/balance
maintain head in upright position and coordination of head/eye movt
where we are in space (w/ visual and prop)
control of mm tone, balance, spatial orientation
What does the vestibular system receive info from
vestibular nuclei (pons/medulla) cerebellum extraocular cranial n vestibulocohlear n vestibular apparatus (semicircular canals, saccule, utricle)
Where is the vestibular appartus located
temporal bony structure
What does the saccule and utricle do
sense static position and linear acceleration
What does the semiciruclar canal do
sense spatial orientation, rotation of head
Where are sensory receptors located
in the vestibular apparatus
Where is the utricular macula when upright
parallel to the ground
Where is the saccular macula when upright
oriented vertically
What do the semicircular canals contain
crista
no otoliths
What do the utriclar macula and saccular macula contain
hair (cilia) with gelatinous substance containing otoliths
What happens in the semicircular canals
cilia of crista are stimulated by movt
What do the anterior and posterior canals detect
rotary movt w/in sagittal plane
What does the horizontal canal detect
rotary movt around the bodys central axis
What is vestibulo-ocular reflex
dolls eye maneuver
when the head is moved to the left the eyes move to the right
What does it mean if someone is missing he vestibulo-ocular reflex
lesion to brain stem or TBI
What is nystagmus
uncontrolled eye movts
When can nystagmus occur w/out vestibular input
viral infections of vestibular system
issues w/ labyrinth, vestibular n or vestibulr nuclei
Lesion in CNS
cerebellar dysfunction (after alcohol)
What is post rotary nystagmus
uncontrolled movt of the eye continues as the semmicircular canals have displaced fluid and it takes awhile to return to normal
when does post rotary nystagmus occur
after passive spinning
what is motion sickness
sensitivity to repeated vertical movt
what is motion sickness characterized by
vertigo
nausea
vomitting
how to prevent motion sickness
antihistamine prior t movt
what is vertigo
false sensation that either the person or world is spinning
what occurs w/ vertigo
dizziness
what is dizziness
sensation of unsteadiness w/ a feeling of movt w/in the head
what may vertigo cause
falls due to false sense of movt
how can vertigo occur
acute- labyrinthitis
chronic-damage to c8-vestibulocochlear n
what is menieres disease
chronic disorder of hearing and prop in the auditory n
what is menieres disease caused by
over accumulation of endolymph w/in the inner ear
s&s of meniere’s disese
severe vertigo
tinnitus (ear ringing)
unilateral hearing loss
prognosis of menieres
meds can reduce severity and preserve hearing but acute vertigo may persist
tx for menieres
med
bedrest
surgery
low salt diet
what is acoustic neuroma
noncancerous and slow growing tumor that develops on the vestibularcochlear n leading from the inner ear to brain
What can acoustic neuroma cause
hearing loss
ringing in your ear
facial numbness
unsteadiness
what is benign paroxysmal positional vertigo (BPPV)
peripheral vestibular disorder affecting the posterior semicircular canal
What causes BPPV
dev of otoliths deposits in posterior semicircular canal
What is a common cause of vertigo
BPPV
clinical signs of bppv
certain head movts produce vertigo
dizziness
nystagmus
how to dx bppv
hallpike dx maneuver (place head in certain posititon, if spinning, positive)
tx for bppv
positions to move deposits out of canal
vibration to break up deposits
vestibular therapy
who does bppv occur in more
60 and older tbi diabetes cva parkinsons viral infection prior problems with vestibular apparatus
characteristics of central dizziness
sudden onset accompanied by headache mod nausea continuous symptoms symptoms don't go away no hearing issues falls to the same side as lesion sometimes has diplopia gen weakness/ataxia
causes of centrl dizziness
brainstem/cerebellum lesion acoustic neuroma drugs veterbral dissection CVA TBI Trauma
characteristics of peripheral dizziness
sudden or slow onset no headache sever nausea/vomitting room or objects seem to move back and forth symptoms can fluctuate or relieve when still blurry vision w/ position changes motion sensitive not associated w/ weakness
causes of peripheral dizziness
BPPV C8 lesion again vestibular neuronitits drug induced
Other causes of dizziness
Vascular insufficiencies (stenosis, occlusions) cardiac insufficiencies (palpitations/arrhythmia/syncope) autonomic neuropathy (diabetes) meds
Tx for central dizziness
adl training AE Patching one eye for diplopia home eval meds vestibular rehab
What is the aqueous humor
transparent fluid that circulates in the eye chamber b/t the back of the cornea and the front of the iris and pupil
