Download The Eye - Quilna Trail Designs

The Eyes and Ears
The Eye
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The eye is a globe shaped, hollow structure set
within a bony cavity
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The bony cavity or orbit houses the eyeball and
assorted structures
Eye muscles
 Nerves
 Blood vessels
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Most of the eyeball is protected from trauma by the
orbit’s bony cavity
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The wall of the eye is comprised of three
layers
Sclera- white outer layer of the eyeball is composed
of fibrous connective tissue
 Cornea- is a transparent domed structure formed by
the sclera
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the cornea also protects the front part of the eye from injury
 Is the first part of the eye that refracts light rays.
 The cornea is avascular (without blood vessels or capillaries)
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Choroid- lies below the sclera
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Contains blood vessels and dark pigmented tissue that
prevents glare within the eyeball by absorbing light.
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Ciliary Body- is the anterior portion of the
choroid
Iris- the colored portion of the eye
Retina- lines the posterior two thirds portion of
the eyeball and contains rods and cones
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The sensory receptors for vision
Rod- a rod-shaped receptor in the retina of the eye that is
sensitive to dim light but not color
 Cone- a cone-shaped cell sensitive to light and color in
the retina of the eye of a human being or any other
vertebrate animal. There are three different types of cone
cells, responding to blue, green, or red light.
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Pupil- the opening in the center of the iris
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Optic disk- the retinal nerve fibers unite here
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The amount of light entering the eye is controlled by
contractions and dilations of the pupil
The optic disk is known as the “blind spot” because
the optic disk has no rods or cones
Optic nerve- formed from the retinal fibers
and cross through the wall of the eyeball
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Myopia
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Nearsightedness
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Hyperopia
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Farsightedness
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Double vision
Emmetropia
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Objects that are not yellow appear as yellow
Diplopia
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Objects that are not red appear red
Xanthopia
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Able to see distant objects better than nearby ones
Erythropia
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Unable to see clearly objects that are far away
Normal vision
Astigmatism
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A defect in a lens that prevents light rays from meeting at a single point
producing an imperfect image (blurred vision)
Emmetropia
Hypertropia
Myopia
Astigmatism
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1. Lacrimal Gland
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1
2
2. Lacrimal Sac
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Is located above the outer
corner or each eye
These glands produce tears,
which keep the eyeballs moist
Collects tears
3. Nasolacrimal ducts
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Tears are drained to the nose
thru the these ducts then
expelled from the body thru
the nose.
3
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Blephar/o
Choroid/o
Corne/o
Cor/o
Dacry/o
Lacrim/o
Dipl/o
eyelid
choroid
cornea
pupil
tear
tear
double
blepharospasm
choroidopathy
corneitis
anisocoria
dacryorrhea
lacrimation
diplopia
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Irid/o
Kerat/o
iris
iridoplegia
horny tissue, hard, cornea
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Ocul/o
Ophthalm/o
Opt/o
Retin/o
Scler/o
keratoplasty
eye
intraocular
eye
ophthalm/o/scope
eye,vision
optic
retina
retinopathy
hardening,sclera scler/itis
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-opia
vision
amblyopia
-opsia
vision
heteropsia
-ptosis prolapse, downward displacement
blepharoptosis
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Achromatopsia- color blindness, more common in
men
Astigmatism- blurred vision due to defect in the
curvature of the cornea and lens
Cataract- opacity (cloudiness) of the lens as result
of protein deposits on its surface that slowly builds
up until vision is lost
Conjunctivitis- inflammation of the conjunctiva
that can be caused by bacteria, allergy, irritation, or
a foreign body; also called “pinkeye”
Diabetic retinopathy- retinal damage marked by
aneurismal dilation of blood vessels
Esotropia- strabismus in which there is
deviation of the visual axis of one eye toward
that of the other eye resulting in diplopia
(double vision) also called “cross eyed”
 Glaucoma- increased intraocular pressure
caused by the failure of the aqueous humor
(the transparent fluid that circulates in the eye
chamber) to drain, which results in atrophy of
the optic nerve and eventually may lead to
blindness.
 Strabismus- muscular eye disorder in which
the eyes turn from the normal position so that
they deviate in different directions
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Hordeolum- small purulent (relating to,
containing, or consisting of pus) inflammatory
infection of the sebaceous gland of the eyelid;
also called a “sty”
 Macular degeneration- breakdown of the
tissues in the macula resulting in loss of central
vision
 Photophobia- unusual intolerance and
insensitivity to light; occurs in diseases such as
measles, meningitis, inflammation of the eyes,
measles and rubella
 Retinal detachment- separation of the retina
from the choroid, which disrupts vision and
results in blindness if not treated.
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Tonometry- measuring of the intraocular
pressure by determining the resistance of the
eyeball to indention by an applied force; used to
detect glaucoma
Visual acuity test- standard test of visual acuity
using the “ E-Chart”
Cataract surgery- excision of cataracts by
surgical removal of the lens
 Corneal transplant- (keratoplasty) surgical
transplantation of a donor cornea (from a
cadaver) into the eye of a recipient
 Extracapsular surgery- excision of most of
the lens, followed by insertion of an
intraocular lens transplant
 Phacoemulsification- excision of the lens by
ultrasonic vibrations that break the lens into
tiny pieces which are then suctioned out of the
eye.
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The Ear
The Ears
 The
ears and their accessory
structures are the receptor
organs that enable us to hear
and maintain our balance.
Each ear consists of three divisions

The external ear, the middle ear, and the inner
ear
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The External and Middle ear
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Conducts sound waves through the ear
The Inner ear
Contains auditory structures that receive the sound waves
and transmits them to the brain for interpretation.
 Contains specialized receptors that maintain balance and
equilibrium regardless of changes in the body position or
motion
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The External Ear
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the outside part of the ear, consisting of the
auricle and auditory canal
Auricle-the part of the external ear that projects
outward from the head ***WARNING*** do not
confuse with the auricle in the heart-an ear-shaped
muscular part that sticks out from the surface of
each upper chamber atrium of the heart.
 Auditory Canal- a passage from the outer ear to the
ear drum along which sound waves travel
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The Middle Ear
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The narrow air-filled space between the ear drum and
the outer wall of the inner ear containing the three tiny
bones that transmit sound vibrations
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1. Incus-a small anvil-shaped bone in the middle ear of
mammals
2. Stapes-a small stirrup-shaped bone in the middle ear of
mammals, the innermost of the three small bones that
transmit vibration to the inner ear
3. Malleus- a hammer-shaped bone, the outermost of three
small bones in the middle ear that transmit sound waves from
the eardrum to the inner ear.
Bones of the Middle Ear
Incus
2. Stapes
3. Malleous
 1.
The Inner Ear
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The fluid-filled part of the ear, including the
cochlea, which is responsible for hearing, and
the semicircular canals, which control balance
Cochlea- a spiral structure in the inner ear that
looks like a snail shell and contains tiny hair cells
whose movement is interpreted by the brain as
sound
 Semicircular canals- each of three tubes in the
inner ear, semicircular in shape and set at right angles
to one another, that help to maintain balance
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Recap of the Ear Structure
Eardrum
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A membrane of thin skin and fibrous tissue that
vibrates in response to sound waves, located
between the external and the middle ear.
Pathology of the Ear
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Acoustic neuroma- a benign tumor that develops on the
auditory nerve causing hearing loss, loss of balance, and
headaches
Anacusis-total deafness; complete hearing loss
Conductive hearing lose- hearing loss due to an impairment in
the transmission of sound because of an obstruction of the ear
canal or damage to the eardrum or ossicles (a small bone,
especially one of three bones of the middle ear in humans)
Meniere disease- rare disorder of unknown etiology within the
labyrinth (structure consisting of connected cavities or canal)
Pathology continued
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Otitis media- a painful inflammation of the middle ear that can
cause dizziness and temporary hearing loss
Otosclerosis- a hereditary disease of the inner ear in which
spongy bone growth leads to progressive hearing impairment
Presbycusis- impairment of hearing resulting from the aging
process
Tinnitus- a continual noise in the ear, e.g. a ringing or roaring,
usually caused by damage to the hair cells of the inner ear
Vertigo- a condition in which somebody feels a sensation of
whirling or tilting that causes a loss of balance
Diagnostic
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Audiometry- test that measures hearing acuity
of various sound frequencies
Otoscopy- visual examination of the ear;
especially the eardrum using an otoscope
Rinne test- hearing acuity test that is performed
with a vibrating tuning fork placed on the
mastoid process, then in front of the external
auditory canal to test bone and air conduction
Therapeutic
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Cochlear implant- electronic transmitter that is
surgically implanted into the cochlea of a deaf
person; performed to restore hearing loss
Myringoplasty- surgical repair of a perforated
eardrum with a tissue graft
Myringotomy-incision of the eardrum to
relieve pressure and release pus or serous fluid
from the middle ear or to insert tympanostomy
tubes surgically in the eardrum
Combining forms
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Acous/o
Audi/o
Myring/o
Tympan/o
Ot/o
Salping/o
hearing
hearing
tympanic membrane
tympanic membrane
ear
tube (usually fallopian
or eustachian)
auditory tube
Suffixes
 -acusis
 -tropia
hearing
turning