1. Chapter 14 The Human Eye
Structure and Function of the Eye (Concept Map)
17 April 2017
Biology Matters textbook page 281 Concept Map

2. Vertical Section of The Human Eye
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3. Vertical Section of The Human Eye
suspensory
ligament
Attaches lens
to ciliary body
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4. Vertical Section of The Human Eye
suspensory
ligament
iris
Controls amount
of light entering
the eye
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5. Vertical Section of The Human Eye
suspensory
ligament
iris
aqueous
humour
Refracts light rays;
keeps eyeball firm
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6. Vertical Section of The Human Eye
suspensory
ligament
iris
aqueous
humour
pupil
Allows light to
enter the eye
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7. Vertical Section of The Human Eye
suspensory
ligament
iris
aqueous
humour
pupil
cornea
Refracts light rays
into pupil
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8. Vertical Section of The Human Eye
suspensory
ligament
iris
aqueous
humour
pupil
cornea
lens
Focuses light rays
onto retina
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9. Vertical Section of The Human Eye
suspensory
ligament
iris
aqueous
humour
pupil
cornea
lens
ciliary
body
Contains ciliary
muscles which
control curvature
or thickness of the
lens
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10. Vertical Section of The Human Eye
suspensory
ligament
iris
aqueous
humour
pupil
cornea
lens
ciliary
body
viterous
humour
Refracts light rays;
keeps eyeball firm
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17 April 2017 10

11. Vertical Section of The Human Eye
suspensory
ligament
rectus
muscles
Controls movement
of eyeball
iris
aqueous
humour
pupil
cornea
lens
ciliary
body
viterous
humour
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12. Vertical Section of The Human Eye
suspensory
ligament
rectus
muscles
iris
sclera
aqueous
humour
Protects against
mechanical injury
pupil
cornea
lens
ciliary
body
viterous
humour
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13. Vertical Section of The Human Eye
suspensory
ligament
rectus
muscles
iris
sclera
aqueous
humour
choroid
Pigmented black to
prevent internal reflection
of light; blood vessels
bring oxygen and
nutrients to the eyeball
pupil
cornea
lens
ciliary
body
viterous
humour
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14. Vertical Section of The Human Eye
suspensory
ligament
rectus
muscles
iris
sclera
aqueous
humour
choroid
pupil
fovea
(yellow spot)
cornea
Region where images are sharply focused
lens
ciliary
body
viterous
humour
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15. Vertical Section of The Human Eye
suspensory
ligament
rectus
muscles
iris
sclera
aqueous
humour
choroid
pupil
fovea
(yellow spot)
cornea
lens
optic nerve
Transmit nerve impulses
from eye to brain
ciliary
body
viterous
humour
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16. Vertical Section of The Human Eye
suspensory
ligament
rectus
muscles
iris
sclera
aqueous
humour
choroid
pupil
fovea
(yellow spot)
cornea
lens
optic nerve
ciliary
body
blind spot
Region over optic nerve; no photoreceptors,
so insensitive to light
viterous
humour
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17. Vertical Section of The Human Eye
suspensory
ligament
rectus
muscles
iris
sclera
aqueous
humour
choroid
pupil
fovea
(yellow spot)
cornea
lens
optic nerve
ciliary
body
blind spot
viterous
humour
retina
Light-sensitive layer containing
cones responsible for colour
vision in bright light and rods
responsible for vision in dim light
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18. Vertical Section of The Human Eye
Pupil Reflex
A reflex action in which the pupil changes size as a result of changes in light intensity.
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19. Vertical Section of The Human Eye
Pupil Reflex
In bright light
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20. Vertical Section of The Human Eye
Pupil Reflex
In bright light
Circular muscles in iris contract.
Radial muscles relax.
Pupil becomes smaller, hence less light enters the eye
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21. Vertical Section of The Human Eye
Pupil Reflex
In bright light
Circular muscles in iris contract.
Radial muscles relax.
Pupil becomes smaller, hence less light enters the eye
In dim light
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22. Vertical Section of The Human Eye
Pupil Reflex
In bright light
Circular muscles in iris contract.
Radial muscles relax.
Pupil becomes smaller, hence less light enters the eye
In dim light
Radial muscles in iris contract .
Circular muscles in iris relax.
Pupil enlarges, hence more light enters the eye
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23. Vertical Section of The Human Eye
Pupil Reflex
Focusing
The adjustment of the lens of the eye so that clear images of objects at different distances are formed on the retina.
In bright light
Circular muscles in iris contract.
Radial muscles relax.
Pupil becomes smaller, hence less light enters the eye
In dim light
Radial muscles in iris contract .
Circular muscles in iris relax.
Pupil enlarges, hence more light enters the eye
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24. Vertical Section of The Human Eye
Pupil Reflex
Focusing
In bright light
Circular muscles in iris contract.
Radial muscles relax.
Pupil becomes smaller, hence less light enters the eye
In dim light
Radial muscles in iris contract .
Circular muscles in iris relax.
Pupil enlarges, hence more light enters the eye
Distant object
(7 metres or more)
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25. Vertical Section of The Human Eye
Pupil Reflex
Focusing
In bright light
Circular muscles in iris contract.
Radial muscles relax.
Pupil becomes smaller, hence less light enters the eye
In dim light
Radial muscles in iris contract .
Circular muscles in iris relax.
Pupil enlarges, hence more light enters the eye
Distant object
(7 metres or more)
Ciliary muscles relax
Suspensory ligament become taut
Lens becomes thinner and less convex
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26. Vertical Section of The Human Eye
Pupil Reflex
Focusing
In bright light
Circular muscles in iris contract.
Radial muscles relax.
Pupil becomes smaller, hence less light enters the eye
In dim light
Radial muscles in iris contract .
Circular muscles in iris relax.
Pupil enlarges, hence more light enters the eye
Distant object
(7 metres or more)
Ciliary muscles relax
Suspensory ligament become taut
Lens becomes thinner and less convex
Near object
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27. Vertical Section of The Human Eye
Pupil Reflex
Focusing
In bright light
Circular muscles in iris contract.
Radial muscles relax.
Pupil becomes smaller, hence less light enters the eye
In dim light
Radial muscles in iris contract .
Circular muscles in iris relax.
Pupil enlarges, hence more light enters the eye
Distant object
(7 metres or more)
Ciliary muscles relax
Suspensory ligament become taut
Lens becomes thinner and less convex
Near object
Ciliary muscles contract
Suspensory ligaments slacken
Lens becomes thicker and more convex
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