Functional Anatomy of the Eye
Explain
Glossary
Chapter 2. Functional Anatomy of the Eye
2.1 Title slide
Demonstration 2.2
true
true
You must read each slide, and complete any questions on the slide, in
sequence.
true
title
Functional Anatomy of the Eye
Interact with a depiction of the human eye.
CLICK ANYWHERE TO BEGIN
The main function of the human eye is to provide the brain with information about “what is where” in the visible world. All the different structures of the eye work in exquisite coordination to accomplish this goal. [Ramón Rivera-Moret]
What Is the Functional Anatomy of the Eye?
The human eye is roughly spherical, with a diameter of about 24 mm (the optic axis is an imaginary diameter line from the front to the
back of the eye).
Three membranes surround the eye:
• The outer membrane is made up of the sclera (a protective covering whose visible portion is the white of your eye) and the transparent cornea at the front of the eye.
• The middle membrane is the choroid; it contains most of the blood vessels that supply the inside of the eye with oxygen and nutrients.
• The inner membrane is the retina, which is made up of neurons, including the receptors that convert the light entering the eye into neural signals.
Light enters the eye by first passing through the cornea, which sharply refracts (bends) the light. The light then passes through the pupil and into the lens, a transparent structure that further refracts the light. The shape of the lens is adjusted to ensure that light focuses properly on the retina.
The pupil is an opening in the middle of the iris, a small donut-shaped muscle. The iris controls the size of the pupil by contracting and relaxing.
The zonule fibers connect the lens to the choroid. The ciliary muscles are also attached to the choroid. When the ciliary muscles relax, the choroid pulls on the zonule fibers, stretching the lens; when the ciliary muscles contract, they oppose the pull by the choroid on the zonule fibers, and the lens isn't stretched as much.
The fovea is the area at the center of the retina, receiving light from objects at the center of gaze. The optic disk is the place where the optic nerve exits the eye and where blood vessels enter and exit the eye.
The anterior chamber is the space between the cornea and the iris; the posterior chamber is the smaller space between the iris and the lens. Both chambers are filled with a fluid called aqueous humor. The large vitreous chamber—the main interior portion of the eye—is filled with a fluid called vitreous humor. The fluids in these chambers exert outward pressure on the eye and keep it from collapsing.
Three membranes surround the eye:
• The outer membrane is made up of the sclera (a protective covering whose visible portion is the white of your eye) and the transparent cornea at the front of the eye.
• The middle membrane is the choroid; it contains most of the blood vessels that supply the inside of the eye with oxygen and nutrients.
• The inner membrane is the retina, which is made up of neurons, including the receptors that convert the light entering the eye into neural signals.
Light enters the eye by first passing through the cornea, which sharply refracts (bends) the light. The light then passes through the pupil and into the lens, a transparent structure that further refracts the light. The shape of the lens is adjusted to ensure that light focuses properly on the retina.
The pupil is an opening in the middle of the iris, a small donut-shaped muscle. The iris controls the size of the pupil by contracting and relaxing.
The zonule fibers connect the lens to the choroid. The ciliary muscles are also attached to the choroid. When the ciliary muscles relax, the choroid pulls on the zonule fibers, stretching the lens; when the ciliary muscles contract, they oppose the pull by the choroid on the zonule fibers, and the lens isn't stretched as much.
The fovea is the area at the center of the retina, receiving light from objects at the center of gaze. The optic disk is the place where the optic nerve exits the eye and where blood vessels enter and exit the eye.
The anterior chamber is the space between the cornea and the iris; the posterior chamber is the smaller space between the iris and the lens. Both chambers are filled with a fluid called aqueous humor. The large vitreous chamber—the main interior portion of the eye—is filled with a fluid called vitreous humor. The fluids in these chambers exert outward pressure on the eye and keep it from collapsing.
2.2 Explain - dnd
explain_dnd
You haven't completed the activity on this screen. However, if you leave
this screen now, any work you've done on the screen will be saved. Are you sure you want to leave?
Drag and drop each of the labels into the correct box on this cross-section
of the eye
viewed from above.
RESET
Anterior chamber
Choroid
Ciliary muscle
Cornea
Fovea
Iris
Lens
Optic axis
Optic disk (blind spot)
Optic nerve
Posterior chamber
Pupil
Retina
Sclera
Vitreous chamber
Zonule fibers
2.3 Explain - dnd
explain_dnd
You haven't completed the activity on this screen. However, if you leave
this screen now, any work you've done on the screen will be saved. Are you sure you want to leave?
Drag and drop each of the labels into the correct box on this cross-section
of the eye viewed from above.
RESET
This is an imaginary line from the front to the back of the
eye.
These are involved in the process of accommodation.
This is the larger chamber filled with aqueous humor.
This is where blood vessels and the optic nerve exit the
eye.
This is the smallest fluid-filled chamber in the eye.
This carries neural signals from the eye to the brain.
This and the zonule fibers work together to control the refraction of light by the
lens.
This chamber isn’t filled with aqueous humor.
Zonule fibers
Posterior chamber
Anterior chamber
Ciliary muscle
Vitreous chamber
Optic axis
Optic nerve
Optic disk (blind spot)
2.4 Explain - dnd
explain_dnd
You haven't completed the activity on this screen. If you leave this screen now, any work you've done on
this screen will be saved. Are you sure you want to leave?
Drag each label on the illustration into the box above the matching description.
RESET
This contains light-sensitive neurons.
Light enters the eye through this opening.
This and the cornea form the protective outer membrane of the eye.
This is a transparent structure at the front of the eye.
This refracts light in precisely controlled ways to focus
light on the retina.
This is where light from objects at the center of gaze strikes the retina.
This membrane contains most of the blood vessels that supply the interior of the
eye.
This controls the size of the opening through which light
enters the eye.
Sclera
Iris
Cornea
Lens
Pupil
Choroid
Fovea
Retina
2.5 Explain
explain_text
What Is the Functional Anatomy of the Eye?
The human eye is roughly spherical, with a diameter of about 24 mm (the optic axis is an imaginary diameter line from the front to the back of the eye).
Three membranes surround the eye:
• The outer membrane is made up of the sclera (a protective covering whose visible portion is the white of your eye) and the transparent cornea at the front of the eye.
• The middle membrane is the choroid; it contains most of the blood vessels that supply the inside of the eye with oxygen and nutrients.
• The inner membrane is the retina, which is made up of neurons, including the receptors that convert the light entering the eye into neural signals.
Light enters the eye by first passing through the cornea, which sharply refracts (bends) the light. The light then passes through the pupil and into the lens, a transparent structure that further refracts the light. The shape of the lens is adjusted to ensure that light focuses properly on the retina.
The pupil is an opening in the middle of the iris, a small donut-shaped muscle. The iris controls the size of the pupil by contracting and relaxing.
The zonule fibers connect the lens to the choroid. The ciliary muscles are also attached to the choroid. When the ciliary muscles relax, the choroid pulls on the zonule fibers, stretching the lens; when the ciliary muscles contract, they oppose the pull by the choroid on the zonule fibers, and the lens isn't stretched as much.
The fovea is the area at the center of the retina, receiving light from objects at the center of gaze. The optic disk is the place where the optic nerve exits the eye and where blood vessels enter and exit the eye.
The anterior chamber is the space between the cornea and the iris; the posterior chamber is the smaller space between the iris and the lens. Both chambers are filled with a fluid called aqueous humor. The large vitreous chamber—the main interior portion of the eye—is filled with a fluid called vitreous humor. The fluids in these chambers exert outward pressure on the eye and keep it from collapsing.
Three membranes surround the eye:
• The outer membrane is made up of the sclera (a protective covering whose visible portion is the white of your eye) and the transparent cornea at the front of the eye.
• The middle membrane is the choroid; it contains most of the blood vessels that supply the inside of the eye with oxygen and nutrients.
• The inner membrane is the retina, which is made up of neurons, including the receptors that convert the light entering the eye into neural signals.
Light enters the eye by first passing through the cornea, which sharply refracts (bends) the light. The light then passes through the pupil and into the lens, a transparent structure that further refracts the light. The shape of the lens is adjusted to ensure that light focuses properly on the retina.
The pupil is an opening in the middle of the iris, a small donut-shaped muscle. The iris controls the size of the pupil by contracting and relaxing.
The zonule fibers connect the lens to the choroid. The ciliary muscles are also attached to the choroid. When the ciliary muscles relax, the choroid pulls on the zonule fibers, stretching the lens; when the ciliary muscles contract, they oppose the pull by the choroid on the zonule fibers, and the lens isn't stretched as much.
The fovea is the area at the center of the retina, receiving light from objects at the center of gaze. The optic disk is the place where the optic nerve exits the eye and where blood vessels enter and exit the eye.
The anterior chamber is the space between the cornea and the iris; the posterior chamber is the smaller space between the iris and the lens. Both chambers are filled with a fluid called aqueous humor. The large vitreous chamber—the main interior portion of the eye—is filled with a fluid called vitreous humor. The fluids in these chambers exert outward pressure on the eye and keep it from collapsing.
2.6 Test - single choice
You must select an answer and then click SUBMIT before you can click proceed
to the next screen.
test_single_choice
Select your answer to the question below. Then click SUBMIT.
Photo © Steve Allen / Getty Images.
This is a normal human retina as seen through an ophthalmoscope. The fovea is the faint dark region at the right center of the photo.
When you look directly at the fovea in this image, light rays from that portion of the image strike which part of your own retina?
A.
the optic disk
B.
the upper part
C.
the fovea
D.
the entire retina
Correct! Click EXPLAIN if you want to review this topic.
Incorrect. The correct answer is C. Click EXPLAIN if you want to review this topic.
2.7 Test - dnd
You must complete the question and then click SUBMIT before you can click proceed to the next screen.
test_dnd
Slide 7/Test Yourself 2: Matching Activity
Drag the labels into the blank boxes from left to right, in the order in which light encounters these structures on its path into the eye. Then click SUBMIT.
DIRECTION OF LIGHT
Retina
Vitreous chamber
Pupil
Cornea
Anterior chamber
Lens
2.8 Test - dnd
You must complete the question and then click SUBMIT before you can click proceed to the next screen.
test_dnd
Slide 8/Test Yourself 3: Matching Activity
Drag each description at left to attach to the matching part of the eye. Then click SUBMIT.
Aqueous and Vitreous humor
Iris and Pupil
Eye
Sclera
Ciliary muscle and Zonule fibers
Cornea
Membrane encasing the eye
Roughly spherical, diameter about 24 mm
Sharply refacts light, more than the lens
Controls the amount of light entering the eye
Maintains the intraocular pressure
Involved in the process of accommodation
2.9 Activity completed
Activity Complete!
You have completed the activity
Functional Anatomy of the Eye.
Functional Anatomy of the Eye.
Sensation & Perception LaunchPad Solo © 2016 Worth Publishers. All rights reserved.