MODULE 8 IQ 5: Technologies & Disorders Flashcards
1
Q
components of the outer ear
A
pinna, external auditory meatus, tympanic membrane
2
Q
outer ear function
A
channel air particle vibrations along the ear canal to cause the tympanic membrane to vibrate which conducts the sound energy into a solid medium
3
Q
pianna composition
A
elastic cartilage covered with thick skin
4
Q
pianna function
A
visible outer ear which functions to capture sound waves and guide them into the auditory canal
5
Q
external auditory meatus composition
A
contains ceruminous glands which secretes ear wax. it also has small hairs which function to trap foreign objects
6
Q
external auditory meatus function
A
guides sound waves to the tympanic membrane
7
Q
tympanic membrane composition
A
thin, connective tissue membrane shaped like a cone that is covered by skin externally and mucuous membranes internally
8
Q
tympanic membrane function
A
separates the outer and middle ear
- vibrates when hit by sound waves to transmit the sound energy further into the solid medium of the ossicles in the middle ear
9
Q
middle ear components
A
ossicles, oval window, round window, eustachian tube
10
Q
middle ear function
A
- converts KE of moving particles to a mechanical vibration through the ossicles to amplify the sound
- protection and noise dampening by changing the flexibility of the tympanic membrane
11
Q
ossicles composition
A
made up of bone and are linked by synovial joints in a chain
12
Q
ossicles function
A
malleus –> connected to tympanic membrane and the incus
incus –> connected to the malleus and stapes
stapes –> connected to the oval window
- connects middle ear to inner ear to allow amplified vibrations to push on oval window, causing fluid in cochlear to move
12
Q
oval window composition
A
membrane covered opening connecting the middle ear and innere ear
12
Q
oval window function
A
transforms vibrations to fluid waves in the cochlear
12
Q
round window composition
A
membrane covered opening
12
Q
round window function
A
relieves pressure created by fluid waves in the cochlear
13
Q
eustachian tube composition
A
canal that links the middle ear to nasopharynx
14
Q
eustachian tube function
A
- equalises pressure across the tympanic membrane with the atmospheric air pressure
- clear out middle ear secretions
- protects the reflux of fluids from the nasopharynx
15
Q
inner ear function
A
- regulating rotational acceleration and position of the head in space which is important for balance
16
Q
semicircular canals composition
A
composed of 3 tubes with fluid inside of it
17
Q
semicircular canals function
A
important in keeping balance and knowing where the head is in space
18
Q
cochlea composition
A
spiral bony chamber that coils around the central axis
19
Q
cochlea function
A
contains the organ of corti and 2 different types of receptors. important in conducting electrical impulses to conduct sound
20
Q
cochlea operation
A
wave moves through fluid-filled canals of the cochlea from the oval window –> causes bending of the hair cells against the tectorial membrane –> transforms kinetic energy of the wave into electrical energy of the nerve impulse sent along the auditory nerve to the brain
21
pitches
high pitch: stimulates hair cells closest to oval window
low pitch: stimulate hair cells on the other end of the cochlea (apex)
22
amplitude
causes vigorous pressure inside the cochlea (hair cells are bent more for loud sounds and will send more nerve impulses)
23
conductive hearing loss definition
a problem with conducting sound through the outer and middle ear which results in reduced sound volume as there is a reduced stimulus to the inner ear
24
conductive hearing loss location
outer and middle ear
25
conductive hearing loss causes
- malformation of outer ear, ear canal or middle ear structure
- ear infection in the outer ear canal or middle ear. accumulation of fluid in the middle ear may interfere with the movement of the eardrum and ossicles
- perforated eardrum --> external injury
- bony growth around the ossicles in the middle ear, preventing it from vibrating when stimulated by sound
26
conductive hearing loss generic symptoms
pain in, on or both ears, sensation of pressure in one or both ears, difficulty for frustration with telephone conversations
27
sensorineural hearing loss definition
damage to the inner ear (cochlea and the nerve pathways to the brain) --> processing and difficulties hearing due to the neural pathways being damaged
28
sensorineural hearing loss location
inner ear (cochlea --> mainly the stereocilia)
29
sensorineural hearing loss cause
- hair cells enlarge and lose resilience --> reduced ability for stereocilia to respond to their vibrations
- benign tumours such as acoustic neuroma grow in the canal connecting the brain to the inner ear
- fatigue of the cochlear hair cells
30
sensorineural hearing loss generic symptoms
inner ear which is responsible for the neural pathways are damaged which results in permanent hearing loss.
31
what does cochlear implant treat
sensorineural hearing loss
32
how is cochlear implant implanted
- surgery --> insert electrode array inside the cochlear and a receiver through an opening into the mastoid bone behind the ear
- external microphone positioned behind ear detects sound and device amplifies it and processor converts into electrical impulses
- transmitter is positioned on the ear --> magnetic attraction to receiver
- electrodes directly stimulate the neurons on the Organ of Corti
33
cochlear implant information
- expensive and limited for distance
- shorter battery life than hearing aids
- most effective for children under 5
- requires professional education therapy programs to assist implant patients with decoding the new sensory input
34
cochlear implant side effects
- nerve injury
- dizziness or balance problems
- loss of hearing
- tinnitus
35
what does bone conduction implants treat
conductive hearing loss
36
how are bone conduction implants implanted
- specialised surgery --> external sound processor that detects sound waves and converts them into vibrations to be passed through the bone to the implant --> moved to inner ear --> sensed naturally by cochlear
37
bone conduction implants information
3 different types:
- abutment through skin
- magnet under skin
- soft headband, non-surgical
38
bone conduction implants side effects
- risk of infection and inflammation at implant site after surgery
- small risk that growth of new bone around implant will fail
- touching incorrect nerve --> change sensory and motor function in face
39
what does hearing aids treat
conductive hearing loss
40
hearing aids structure
microphone = detect sound
device = modulate sound
amplifier = increase the sound volume
battery = power these functions
- amplify sound vibrations that pass into the ossicles so the tympanic membrane and cochlear have adequate level of function
41
hearing aids information
- fitted early as possible to avoid period of sensory deprivation in brain --> auditory regions of the brain may forget how to interpret sound
42
hearing aids side effects
- headaches and tinnitus
- skin irritation, soreness and discomfort
- improper sound level and quality of feedback
43
eye: conjunctiva description
thin layer of mucuous membrane lining the inner surface of each eyelid, moves over the eyeball as a protective cover
44
eye: conjunctiva function
lubricate and nourish the eye, protects the front of the eye
45
eye: cornea description
convex, transparent coating of the eye made up of collagen rich epithelial cells
- covers pupil and iris allowing light to pass through the lens (dense, non-vascular, uniform in thickness and projects like a dome beyond the sclera)
- corneal curvature varies in different individuals
46
eye: cornea function
to refract light and allow it to be focused on the cells of the retina
47
eye: sclera description
touch, opaque membrane of the eye bulb which maintains size and form of the bulb and attaches to muscles that move the bulb
48
eye: sclera function
to protect the inner parts of the eye and help keep its spherical shape
49
eye: choroid description
thick, highly vascular membrane on which the retina rests
50
eye: choroid function
to provide nutrients to the back of the eye, provides blood supply for the retina, black pigment prevents false images by absorbing stray light, forms the iris
51
eye: pupil description
circular opening in iris through which light passes to the lens and the retina
- located behind the anterior chamber of the eye and the cornea in front of the lens
- diameter changes with contraction and relaxation of muscular fibres of the iris as eye responds to changes in light, emotional states and other stimulation
52
eye: pupil function
changes size to control the amount of light entering through the lens/retina
53
eye: retina description
sensory layer at the back of eyeball, holding cone and rod photoreceptor cells and neurons which transmit visual impulses from sensory cells through the optic nerve to the brain
54
eye: retina function
converts light stimuli to electrochemical signals in the nerves
55
eye: iris description
extension of choroid, coloured muscular ring around pupil
56
eye: iris function
muscles contract or dilate to regular size of pupil, colour pigment blocks excess light
57
eye: lens description
biconvex flexible disc made of cells with clear crystallin protein
58
eye: lens function
blocks UV rays, changes shape to focus light rays onto retina
59
eye: aqueous humour description
clear thick liquid held between cornea and lens
60
eye: aqueous humour function
lubricates cornea and lens, helping hold eyeball shape, refracts light as well as providing nourishment to cells in front of the eye
61
eye: vitreous humour description
clear, jelly-like filling in the back of eyeball between lens and retina
62
eye: vitreous humour function
provides support for back of eye so light transmission to retina is clear and free of obstruction. made up of mostly water but contains some salts, glucose and WBC to prevent infection
63
eye: ciliary body description
encircles lens with suspensory ligaments and ciliary muscle as well as producing aqueous humour
64
eye: ciliary body function
holds lens in position and changes it thickness
65
eye: optic nerve description
connection between eye and brain for visual messages, right optic nerve goes to left side of the brain and the left optic nerve to right side of brain
66
eye: optic nerve function
carries nerve signals about images seen from retina to visual cortex of the opposite side of the brain
67
photoreceptors description
responsible for human's perception of vision and are located in the retina of the human eye --> light sensitive pigments that absorb light energy --> information --> electrochemical signals that brain interprets
68
cones
responsible for colour vision and fine detail --> function best under daylight conditions and are most concentrated in region of the retina called the fovea
68
accommodation reflex
eye has ability to view objects/ images at different distances.
distant: ciliary muscles relax --> draws sclera back --> lens elongates, curvature decreases --> reduced refraction of light
close: ciliary muscles contract --. draws sclera forward --> lens rounds, curvature increases --> refraction increases
68
rods
responsible for night vision and are located in the peripheral retina
69
hyperopia definition
axial length of eye is too short for the refractive power of the cornea and lens, causing light to be focused behind retina (far-sightedness)
70
what is used to correct hyperopia
convex or converging lens
71
hyperopia causes
eyeball being too short or curvature of cornea being too short
72
myopia definition
axial length of eye is too long for the refractive power of cornea and lens, causing light to be focused in front of the retina (short-sightedness)
73
what is used to correct myopia
concave or diverging lens
74
myopia causes
eyeball being too long or curvature of cornea being too high
75
presbyopia definition
increased age causes change in lens curvature due to decline in elasticity of lens --> decrease in strength of the ciliary muscle --> reduced accommodation
76
what is prebyopia corrected with
magnifying reading glasses
77
prebyopia cause
old age
78
cataracts
eye's lens becomes cloudy resulting in reduced visual acuity
79
spectacles for myopia
concave lens (diverges light)
- bends light rays outward
- extends focal length of light rays so focused image falls on the retina
80
spectacles for hyperopia
convex lenses (converges light)
- bends light rays inwards
- converge before they reach the eye, shortening focal length
81
LASIK surgery steps
1. anaesthetic applied to cornea and marked with water-soluble marker
2. suction ring is placed on eye
3. thin flap of cornea is cut from surface of eye
4. flap pulled to one side, reveals part of cornea underneath
5. computer-controlled excimer laser cuts into cornea and reshape it to required dimensions
82
cataract surgery steps
1. eye is numbed with local anaesthetic, incision made in cornea and lens capsule
2. phacoemulsifier inserted into incision --> breaks lens into fragments using ultrasonic vibrations
3. fragments of lens are suctioned out
4. artificial intraocular lens is implanted
83
kidney function
filtering blood from harmful substances, regulate blood pH, volume, pressure and osmolality, produce hormones
84
kidney cortex function
contains filtering apparatus, blood vessels, renal corpuscles, renal tubules
85
kidney medullar function
contains major vessels, made up of renal pyramids and columns, contains collecting ducts which relieves the urine to the minor calyxes
86
kidney renal pyramid function
cone-shaped tissues, formed by straight parallel segments of nephrons
87
kidney renal lobes function
portion consisting of a renal pyramid and renal cortex above
88
kidney renal columns function
spaces between renal pyramids and contained interlobular blood vessels
89
kidney minor calyx function
transports urine from collecting ducts --> major calyces
90
kidney major calyx function
transports urine --> renal pelvis
91
