Download Special Senses: The Eyes and Ears

SPECIAL SENSES:
The Eyes and Ears
Learning Objectives
1.
2.
3.
4.
Describe the functions and structures of the
eyes and adnexa.
Recognize, define, spell, and pronounce terms
related to the pathology and diagnostic and
treatment procedures of eye disorders.
Describe the functions and structures of the
ears
Recognize, define, spell, and pronounce terms
related to the pathology and diagnostic and
treatment procedures of ear disorders.
Key Word Parts
Blephar/o
-cusis
Dacrocyst/o
Irid/o
Kerat/o
-metry
Opthalm/o
-opia
Ot/o
Presby/o
Pseud/o
Retin/o
Scler/o
Trop/o
Tympan/o
Major structures and their functions
Eyes (op/ti, opt/o, optic/o, opthalm/o)
receptor organs for the sense of sight.
Receive images and transmit them to the
brain.
Adnexa of the eye – accessory structures
that provide external protection and
movement for the eyes.
Lacrimal apparatus (lacrim/o, dacry/o)
produces, stores, and removes tears.
Major structures and their functions
Lens (phac/o) focuses rays of light on the
retina.
Iris (ir/i, ir/o, irid/o, irit/o) controls the
amount of light entering the eye.
Retina (retin/o) converts light images into
electrical impulses and transmit them to the
brain.
Terminology pertaining to the eyes
Optic
Ocular
Extraocular – outside the eyeball
Intraocular – within the eyeball
Adnexa of the Eyes
Also known as adnexa oculi
• Orbit (eye socket)
• Eye muscles
• Eyelids
• canthus
• Eyelashes
• Conjunctiva
• Lacrimal apparatus
Adnexa of the Eyes
The Eyeball
Also known as the globe
Made up of three layers:
• Sclera known as the white of the
eye
• Cornea is the transparent
anterior portion of the sclera.
• Choroid
• Retina
The Eyeball
The Iris, Pupil, and Lens
Iris – pigmented (colored) muscular layer
that surrounds the pupil.
Pupil – black circular opening in the center
of the iris that permits light to enter the eye.
Lens – clear, flexible, and curved structure
that focuses images of the retina.
The Uveal Tract
Vascular layer of the eye
The Eye
The Retina
Sensitive inner nerve
layer of the eye.
Rods – light sensitive
cells, black and white
receptors
Cones – color
receptors
Macula lutea is the
area of sharpest
central vision.
Segments of the Eye
Anterior chamber
• Aqueous fluid
Posterior chamber
• Vitreous humor
• Soft, clear, jelly-like mass
aids the eye in
maintaining its shape.
Normal Action of the Eyes
Accommodation
• Seeing objects at various distance
• Pupil dilate/constrict
Convergence – simultaneous inward
movement of both eyes to maintain single
binocular vision.
Emmetropia
Refraction
Visual Acuity
Normal vision as 20/20
Snellen Chart
• Indicates the distance from the chart
which is standardized at 20 feet. (first
number)
• Indicates the deviation from the norm
based on the ability to read lines of letters
on the chart. (second number)
Pathology of the Eyes
The Eyelids
• Blepharoptosis
• Ectopion
• Entropion
• Hordeolum
• Chalazion
Pathology of the eyelids
Conjunctivitis
Adnexa Pathology
• Dacryocystitis
• Conjunctivitis
• Xerophthalmia – also
known as dye eye, drying
of the eye surfaces
characterized by the loss of
luster of the conjunctiva
and cornea
Sclera, Cornea, and Iris
Scleritis
Keratitis
Corneal abrasion
Corneal ulcer
Iritis
Synechia
Scleritis, Iritis, synechia
100
50
0
1st
Qtr
3rd
Qtr
East
West
North
The Eye
Anisocoria
Cataract
Choked disk
Floaters
Nystagmus
Retinal detachment
Uveitis
Cataract
Glaucoma
It is an eye disease where the fluid
pressure within the eyeball is too high and
damages the optic nerve, which carries
visual impulses from the eye to the brain.
This pressure build-up occurs because of
an imbalance between the production and
drainage of fluid within the eyeball.
Glaucoma
Macular Degeneration
Age-related macular degeneration
(AMD) is a major public health problem.
It is the most common cause of visual
loss in developed countries in
individuals over the age of 60. It is
estimated that by the year 2000, more
than 2 million people in the United
States will be afflicted with this serious
sight-threatening disorder.
Macular Degeneration
The Eye
Functional Defects
Diplopia
Hemianopia – blindness in one half of the
visual field
Monochromatism
Nyctalopia – night blindness
Presbyopia
Strabismus - squint
Esotropia –cross eye
Exotropia – wall eye
The Eye
Refractive Disorders
Ametropia – out of proportion (finite distance)
Astigmatism –unequal curvature of the lens
Hyperopia - farsightedness
Myopia - nearsightedness
Blindness
Amblyopia - dimness
Legal Blindness – 20/200
Scotoma - blindspot
Esotropia & Exostropia
Routine Diagnostic
Visual acuity
Refraction
Tonometry
Specialized diagnostic
Fluorescein staining
Intravenous fluorescein
angiography
Visual field test
Tonometry
This standard test
determines the fluid
pressure inside the eye.
There are many types of
tonometry. One type uses
a purple light to measure
pressure. Another type is
the "air puff," test, which
measures the resistance
of the eye to a puff of air.
Treatment and Diagnostice
Procedures of the Eyes
Visual acuity measurement
Refraction
Tonometry
Dilation of the pupils using
mydriatic drops
Fluorescein staining
Visual field test
Intravenous fluorescien
angiography
Orbitotomy
Tarsectomy
Tarsorrhahpy
Conjunctivoplasty
Corneal transplant 0r
keratoplasty
Iridectomy
Radial keratotomy
(RK)
Abbreviations relating to the eyes
and ears
OD – right eye
OS – left eye
OU – each eye or both eye
AD - right ear
AS – left ear
AU – each ear or both ears
The special Senses
Medical specialties related to the
Eyes and Ears
Audiologist
Ophthalmologist
Optometrist
Otorhinolaryngologist
Structures of the Ears
Outer ear
• Pinna also known a auricle
• Catches sound waves and transmit them
into the external auditory canal
• Cerumen or earwax
Middle ear
• Tympanic membrane or TM or eardrum
Structures of the Ears
Inner ear – also known as labyrinth
contains the sensory receptors for hearing
and balance
Structures and functions
Ears (acous/o, acout/o, audi/o, audit/o, ot/o)
receptor organs for the sense of hearing;
also help to maintain balance
Outer ear (pinn/i) transmits sound waves to
the middle ear
Middle ear (myring/o, tympan/o) transmits
sound waves to the inner ear
Inner ear (labyrinth/o) receives sound
vibrations and transmits them to the brain
Pathology of the Ears
Acute Otitis media
Chronic otitis media
The Special Senses
Serous otitis media
The Special Senses
Mastoiditis
otomycosis
The Ears
Diagnostic Procedures:
Audiometry
Audiometer
Tympanometry
Otoplasty
SPECIAL SENSES:
The Eyes and Ears
The End