Transcript Parts of the Eye - Sarah E. Goode STEM Academy

Healthy Eyes and Ears
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Eyes and ears are sensitive organs
that need protective care.
sclera
cornea
retina
auditory ossicles
labyrinth
tinnitus
Your Eyes
The eyes and their supporting structures are
a complex of parts.
The eye collects light and sends signals to the
brain, where images are formed.
Your Eyes
Your eyes sit in bony sockets, called orbits, at the
front of your skull.
A layer of fat cushions each eyeball inside its
socket.
Your Eyes
The lacrimal gland secretes tears into the eye
through ducts.
Tears keep the surface of the eyeball moist and
clear of foreign particles.
Parts of the Eye
sclera
choroid
vitrius humor
optic nerve
retina
cornea
iris
pupil
lens
aqueous
humor
Parts of the Eye
The sclera is composed of tough, fibrous tissue.
Sclera
The white part of the eye
Parts of the Eye
At the front of the eye rests the cornea.
Cornea
A transparent tissue that
bends and focuses light before
it enters the lens
Parts of the Eye
The retina contains millions of light-sensitive cells
called rods and cones, each named for its basic
shape.
Retina
The inner layer of the
eye wall
Parts of the Eye
Rods are light sensitive cells that allow us to see in
dim light.
Cones are light sensitive cells that allow us to see
in bright light and in color .
Parts of the Eye
Sclera
Protects the inner eye and supports and
shapes the eyeball
Cornea
Bends and focuses light before it enters the lens
Choroid
Lines the inside of the sclera
Iris
Contracts and dilates the pupil
Pupil
Regulates the amount of light that reaches the
inner eye
Parts of the Eye
Retina
Contains light-sensitive cells
Optic Nerve
Transmits nerve impulses to the brain
Lens
Helps refine the focus of images on the retina
Aqueous Humor
Provides nutrients to the eye
Vitreous Humor
Helps the eyeball stay firm and keeps the
retina in place
Vision
Light rays are first focused by the curved cornea,
then later refined by the lens onto the retina.
This light stimulates the rods and cones in the
retina, sending nerve impulses to the brain through
the optic nerve.
Vision
Eye doctors refer to clear, sharp, normal vision as
20/20 vision.
Other components of vision include eye
coordination, peripheral or side vision, and depth
perception.
Vision
Common Vision Disorders
Nearsightedness,
or Myopia
The inability to see distant objects clearly
Farsightedness,
or Hyperopia
The inability see close objects clearly
Astigmatism
Blurred vision
Strabismus
Eyes off-center, turned inward or outward
Detached Retina
Blurred vision or bright flashes of light
Vision
Common Vision Problems
Infections and
Viruses
Swelling, irritation, blurred vision, change in
sclera color
Glaucoma
Cloudy, impaired vision, can cause permanent
damage
Cataracts
Foggy vision
Macular
Degeneration
Vision loss
Keeping Your Eyes Healthy
Making healthy choices will keep your eyes
healthy.
A healthy diet is a critical component for
maintaining eye health.
Keeping Your Eyes Healthy
Follow a wellbalanced eating plan.
Tips for
Keeping Your
Eyes Healthy
Protect your eyes.
Rest your eyes
regularly.
Get regular eye
exams.
Your Ears
The inner, middle, and outer ear work
together so you can hear.
The ear has two functions: hearing and balance.
Your Ears
Your Ears
Parts of The Outer Ear
Function
Auricle
Channels sound waves into the external
auditory canal
External
Auditory Canal
Channels sound waves from the auricle to the
eardrum
Eardrum
Acts as a barrier between the outer and
middle ear
Your Ears
Parts of The Inner Ear
Function
Auditory
Ossicles
Connect the eardrum to the inner ear
Eustachian
Tube
Connects the middle ear to the throat
Your Ears
The auditory ossicles lie in the middle ear directly
behind the eardrum.
Auditory ossicles
Three small bones linked together
that connect the eardrum to the
inner ear
Your Ears
The labyrinth consists of a network of curved and
spiral passages in the inner ear.
Labyrinth
The inner ear
Your Ears
The labyrinth has three main parts.
The cochlea, a spiral-shaped canal, is the
area of hearing in the inner ear.
The vestibule and the semicircular canals are
where balance is controlled.
Hearing and Balance
Receptors cells within the cochlea send nerve
impulses to the brain, where sound is interpreted.
Receptor cells in the vestibule and the semicircular
canals send nerve impulses to the brain, and the
brain makes adjustments to maintain balance.
Keeping Your Ears Healthy
Caring for your ears helps prevent irritation,
injury, infection, and damage to the ears, as
well as hearing loss.
Have your ears examined by a health care
professional if you suspect an infection.
Keeping Your Ears Healthy
Tips for Keeping Your Ears Healthy

Wear a hat that covers both the auricles
and the earlobes in cold weather.

Wear protective gear, such as a batting
helmet, when playing sports.

Keep foreign objects, including cottontipped swabs, out of the ear canal.
Keeping Your Ears Healthy
A health care professional will
check your ears during a
routine physical examination.
Preventing Hearing Loss
Exposure to loud noises can lead to temporary and
sometimes permanent hearing loss, or deafness,
over time.
Conductive Hearing Loss
In conductive hearing loss, sound waves are not
passed from the outer ear to the inner ear, usually
because of a blockage or injury to the inner ear.
Sensorineural Hearing Loss
Sensorineural hearing loss may result from a birth
defect, exposure to noise, growing older, and
medication problems.
Sensorineural Hearing Loss
To prevent tinnitus, avoid loud music, wear
earplugs in noisy environments, and at loud
concerts or sporting events.
Tinnitus
A condition in which a ringing, buzzing,
whistling, roaring, hissing, or other sound
is heard in the ear in the absence of
external sound
After You Read
Reviewing Facts and Vocabulary
1. What happens to eyes that have
cataracts?
The lenses become cloudy and cannot
focus light.
After You Read
Reviewing Facts and Vocabulary
2. What is astigmatism?
Blurred vision due to a misshapen cornea
or lens
After You Read
Reviewing Facts and Vocabulary
3. Explain the function of the wax and tiny
hairs in the ear canal.
Protecting the ear from dust and foreign
objects.