sensory system Flashcards
what is the pupil
the hole in the middle of the eye where light passes
what is the function of the pupil
it is where light passes
what is the iris
the visible coloured ring that adjusts to control the amount of light entering the pupil
what is the function of the iris
to adjust to control the amount of light entering the pupil
what is the cornea
the transparent psrt at the front of the eye
it is protected by the conjunctiva
what is the retina
inner lining of the eye that contains rods and cones
what is the function of the lens
focuses light entering the eye
what is the optic nerve
where nerve cells exit the eye to the brain
what are the malfunctions of the eye
Glaucoma
Cataracts
Retinopathy
Age related Macular Degeneration (AMD)
how is is glacuoma formed
- pressure in the eyeball is caused by vitreous humour fluid building up and not draining properly
- the tear ducts gets blocked/narrow with age
- the build up of pressure causes fluid to press on the optic nerve, destroying it and causing blindness
what are the causes of glaucoma
Age - tear ducts block/narrow with age
High blood pressure - increases amount of fluid in eye
Genetic link
what are the symptoms of glaucoma
Blurred vision
Eye pain
what are the treatments of glaucoma
eye drops to open up the drainage channel in the eye
how is glaucoma diagnosed
a detailed eye test
what are cataracts
Cloudy patches of protein that develop in the lens of the eye, causing blurry vision as light can’t hit the retina properly
what are causes of cataracts
Age
Smoking
what are symptoms of cataracts
Blurry vision and difficulty seeing in low light
Poor night vision and halos around light
what are treatments of cataracts
surgery to remove and replace affected lens
how is cataracts diagnosed
retinal check
what is retinopathy
when high blood sugar levels damage the cells of the retina by weakening the small vessels and causing them to leak
Linked to diabetes
what is the cause of retinopathy
Diabetes
what are symptoms of retinopathy
Blurred vision and floaters in field of vision
how is retinopathy treatment
Lifestyle changes - diet and treatment for diabetes
Regular eye exams
how is retinopathy diagnosed
dialted eye check
what is age related macular degeneration (AMD)
A painless eye condition that results in the loss of central vision
Peripheral vision isnt affected
what are the affects of age related macular degeneration (AMD)
- vision gradually blurs,
- reading becomes difficult - unemployment
- dulls colours
- affect facial recognition
what are the two types of age related macular degeneration (AMD)
Dry AMD
Wet AMD
what happens in dry age related macular degeneration (AMD)
cells in macula become damaged due to deposits of drusen
what happens in wet age related macular degeneration (AMD)
abnormal blood vessels form underneath the macula and damages its cells
what are causes of age related macular degeneration (AMD)
Age
what are treatments of age related macular degeneration (AMD)
Medication
Eye drops
Laser eye surgery
what are symptoms of age related macular degeneration (AMD)
Blurred central vision and difficulty reading
Straight lines appear wavy
Hallucinations
Objects may look smaller than they are
Faded colours
what are the functions of the ear?
- hear sound
- detect motion
- maintain balance
what are the sections of the ear?
External (outer) ear
Middle ear
Inner ear
what is the outer ear made of?
cartilage
what is the function of the outer ear?
collect sound waves and channels it into the ear canals
what is the function of the inner ear?
Transform vibrations into electrical impulses that then travel along the auditory nerve to the brain
what is the function of the middle ear?
Transmits sound waves from external environments to inner ear
why does the middle ear need to remain at the right pressure?
For the ear drum to vibrate correctly and prevent it from bursting
where is the ear drum?
Middle ear
Right at the end of the ear canal
what is the ear drum?
a thin flap of skin that stretches tight and vibrates when sound hits it
what are the auditory ossicles?
Malleus, incus and stapes
Small bones in middle ear
where is malleus, incus and stapes found?
middle ear
what is the function of malleus, incus and stapes?
transmit air vibrations to inner ear so they can be processed as sound
what is the function of the ear drum?
Vibrates when sound hits its
The vibrations move tiny bones in middle ear, sending it to inner ear
where is the cochlea?
Inner ear
what is the cochlea?
a fluid filled cavity in the inner ear
what is the role of the cochlea?
Protect ear from damage
Convert vibrations into electric impulses
where is the organ of corti?
in the cochlea
what is the function of the organ of corti?
Convert sounds into impulses that can be transmitted to brainstem through auditory nerve
where is the eustachian tube?
middle ear
what are the functions of the Eustachian tube?
Balance pressure in the middle ear
Drain fluid from middle ear
Protect middle ear from sound pressure
where is the round window?
middle ear
what is the function of the auditory nerve?
transfer auditory information from cochlea to brain
where is the semicircular canals?
inner ear
what is the function of the semicircular canals?
fluid-filled tubes helping to keep balance
what is the malfunctions of the ear?
deafness
what are the two types of hearing loss?
Conductive hearing loss
Sensorineural hearing loss
what causes deafness?
Some are born without hearing, but most deafness is caused by illness, injury to head, aging, exposure to loud noise, damage to components in ear
what are symptoms of deafness?
Sound is quiet
Tinnitus
what is the treatment of deafness?
medical intervention
what are the causes of conductive hearing loss?
- When sound is unable to pass to middle ear
- Blockage (e.g. earwax) or build up of fluid from infection
- perforated ear drum
- disorder of hearing bones
what is the disorder of hearing bones?
when the bones become fused and don’t pass sound across the middle ear
what are the causes of sensorineural hearing loss?
- Damage to sensitive hair cells in the organ of corti in inner ear
- damage to auditory nerve
what is mixed hearing loss?
when someone experiences sensorineural hearing loss and conductive hearing loss
what are the aids for hearing?
Hearing aids
Lip reading/ sign language
Cochlear implants
what are hearing aids?
Small digital or analogue amplifying devices worn in/behind the ear(s) to magnify sound
what are cochlear implants?
Small devices that detect sounds and send impulses to the brain
