April 26, 2011: Tuesday
Today’s Agenda
New Seating Chart
A. Journal Questions:
1. Where does most nutrient absorption
occur within your digestive system?
2. What is peristalsis?
*B. Lecture II: Eye Anatomy & Function.
Ending on Slide 26
C. Color Anatomical Structures of the Eye
D. Discovery Video: Sight & Sensation
E. Homework: Study for Next week’s exam:
Exam on Monday: Lobes of the brain, the
eye, Digestion, Absorption, and Excretion.
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By Dr. Rick Woodward
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Visual Disorders:
A. Myopia = Nearsightedness:
(1) Individuals can only see
things that are close to them.
-distant objects look blurry.
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By Dr. Rick Woodward
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The Function &
Anatomy of the Eye
By Dr. Rick Woodward
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Eye Charts
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Anatomy Terminology
A.
B.
C.
D.
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Anterior = Front
Posterior = Back
Ventral = Belly
Dorsal = Top
By Dr. Rick Woodward
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The Eyeball is Composed of 3 Layers:
1. Fibrous Tunic
(Connective tissue)
2. Vascular Tunic
(Receives blood)
3. Nervous Tunic (Retina:
Receives impulses from
the nervous system)
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By Dr. Rick Woodward
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The Eyeball is Composed
of 3 Layers:
1. Fibrous Tunic: The outer
coat of the eyeball.
(1) Cornea
(2) Sclera
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By Dr. Rick Woodward
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The Eyeball is Composed
of 3 Layers:
(1) Cornea: Anterior portion of the
fibrous tunic
a. Nonvascular, transparent coat
which covers the pigmented iris.
b. Function: Helps focus light.
(Most important refracting surface
of the eye.)
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By Dr. Rick Woodward
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The Eyeball is Composed of 3
Layers:
(2) Sclera: Posterior portion of the
fibrous tunic.
a. Also called the “white” of the eye.
b. Function: Gives shape to the
eye.
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By Dr. Rick Woodward
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The Eyeball is Composed
of 3 Layers
2. Vascular Tunic – The
middle layer of the eyeball.
(1) Choroid: Posterior
portion of the vascular
tunic.
a. Provides blood supply
and absorbs light rays.
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By Dr. Rick Woodward
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The Eyeball is Composed
of 3 Layers
(2) Ciliary Body: Anterior portion
of the vascular tunic.
a. Composed of two structures:
(1) Ciliary Process (folds
of ciliary body): Secretes
aqueous humor.
(2) Ciliary Muscle: Smooth
muscle that alters the
shape of the lens.
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By Dr. Rick Woodward
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The Eyeball is Composed
of 3 Layers
(3) Iris: Anterior portion of the
vascular tunic.
a. Pigmented doughnut-shaped
structure composed of muscle
fibers.
b. Function: Regulates the
amount of light that enters the
eye.
c. Pupil: Black hole in the
center of the iris through which
light enters the eyeball.
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By Dr. Rick Woodward
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The Eyeball is Composed
of 3 Layers
3. Nervous Tunic (Retina) –The
inner coat of the eyeball.
a. Found only in the posterior
portion of the eyeball.
b. Function: Image formation.
(1) Receives light and
converts light into nerve
impulses, it then transmits
the information to the optic
nerve and then to the
occipital lobe of the brain
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The 2 Layers of the
Retina:
1. Outer pigmented layer
(non-visual portion)
2. Inner nervous tissue
layer (visual portion)
a. Contains
Photoreceptors:
(1) Rods
(2) Cones
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Function of the Rods:
A. Specialized for vision
and dim light.
B. Discrimination between
different shades of dark
and light.
C. Allows us to see shapes
and movement.
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By Dr. Rick Woodward
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Function of the Cones:
A. Color vision and visual
acuity (sharpness of vision)
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By Dr. Rick Woodward
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The Lens
A. Located behind (posterior) the
pupil and iris.
B. The lens is avascular and
normally transparent
“Cataract = loss of transparency”
C. Suspensory Ligaments hold
the lens in position
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The Lens
D. Function: Focus light
rays for clear vision.
E. Contact lenses work by
conforming to the
curvature of the cornea.
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By Dr. Rick Woodward
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The Interior of the Eyeball
A. Composed of two cavities:
(1) Anterior Cavity (located
anterior to the lens)
a. Anterior Chamber
b. Posterior Chamber
(2) Posterior Cavity (located
between the lens and the
retina)
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By Dr. Rick Woodward
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Anterior Chamber
A. Located in front (anterior)
of the iris and behind the
cornea.
(1) Filled with aqueous
humor
(2) Pressure is kept within
normal limits by drainage of
aqueous humor through the
Canal of Schlemn.
-Glaucoma is characterized
by an increase in
intraocular pressure.
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By Dr. Rick Woodward
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Posterior Cavity
A. Located between
the lens and the
retina.
B. It is a much
larger cavity.
C. It contains
vitreous humor;
which helps
prevent the
eyeball from
collapsing.
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By Dr. Rick Woodward
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Start to Study for Your Exam
It will cover: Eye, Digestion,
Absorption, Excretion,
Use your lecture notes, handouts,
Film: Your Exam is next Monday
Sheep Eye Dissection Coming up Next!
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By Dr. Rick Woodward
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