The Nervous System -- The Eye and Ear
18
Name: _________________________ Date: ______ Period: ___
25 24 23 22 21 20
19 18 17 16 15 14 13 12 11
10 9 8 7 6 5 4 3 2 1 0
Big Question:
Each of your major senses such as vision, hearing, or smell, picks up a specific type of
information about your environment. The senses are parts of our nervous system. The sense
organs, such as eyes, ears or nose change stimulations into nerve signals and send the signals to
the brain. Your brain then interprets the signals as what we call seeing, hearing or smelling.
Your eyes are the sense organs that respond to the stimulus of light. Your ears are the sense
organs that respond to the stimulus is vibrations of molecules.
I) How We See
A) Light: Light is reflected from the objects around us. The eye
transforms light into electrical signals that are sent to the brain.
B) Cornea: Transparent layer that covers the entire surface of the
eyeball that protects the eye and focuses light on the retina.
C) Pupil: The hole in the center of the eye for light to pass
through.
D) Iris: Tiny muscles that make the pupil larger or smaller
depending on how much light the eye needs. It is the colored
part of the eye.
E) Lens: Focuses light on the retina.
F) Retina: Receptor cells in the retina convert light into electrical
signals.
G) Optic Nerve: Transfers electrical signals to the brain.
H) Brain: Interprets electrical signals (nerve impulses) as images.
II) How We Hear
A) Vibrations: Molecules can vibrate (move back and forth).
B) Sound Waves: Vibrations of molecules. The waves travel
because the molecules hit one another. The ear transforms
vibrations of molecules into electrical signals that are sent to
the brain.
C) Outer ear: Visible part of the ear, ear canal, ear drum. Sound
travels through the ear canal to the ear drum and vibrates it.
D) Middle ear: Consists of three (3) small bones:
1) Hammer
2) Anvil
3) Stirrup
E) Vibrations: Vibrations of the ear drum are passed to the
hammer. The hammer passes vibrations to the anvil. The anvil
passes vibrations to the stirrup.
F) Inner ear: Vibrations from stirrup are transferred to the fluid
in the cochlea.
G) Receptor cells: The receptor cells in the cochlea convert
vibrations into electrical signals.
H) Auditory Nerve: Transfers electrical signals (nerve impulses)
to the brain.
I) Brain: Interprets electrical signals as sound.
Rev: 3/22/2016
The Nervous System -- The Eye and Ear
1.
The cochlea
A. Separates the outer ear from the inner ear.
B. Is one of the three tiny bones in the middle ear.
C. Enables the outer ear to gather sound waves.
D. Is lined with receptor cells that convert sound
to nerve impulses (electrical signals).
2.
The semicircular canals help you to
A. Maintain balance.
B. See.
C. Hear.
D. Focus light on a particular area of the brain.
3.
The structure that is made of receptor cells
which convert light into nerve impulses is the
__________________.
4.
The structure that regulates the amount of light
entering the eye and gives the eye its color is the
_________________.
5.
The opening (hole) through which light enters
the eye is the _____________.
6.
True or False? Hammer, Anvil and stirrup are
all made of cartilage.
7.
The structure behind the pupil that focuses light
on the retina is the ____________.
8.
True or False? Sound waves can travel only
through gases like air.
9.
The membrane that vibrates when sound waves
strike it is called
A. Outer ear.
B. Hammer.
C. Anvil.
D. Ear drum.
10. The clear tissue that covers the front of the eye is
the ____________.
10
9
8
7
6
5
4
3
2
1
0
Mini-Essay (10 pts) Read, Understand, and Answer: “The eye does not see and the ear does not hear.
It is the brain that sees and the brain that hears.” Explain in your own words what this statement
means..
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Self:
10
9
8
7
6
5
4
3
2
1
0
Honest and fair self-evaluation helps you improve.
Other:
10
9
8
7
6
5
4
3
2
1
0
You are evaluating the work of the person
NOT the person.
If your handwriting is hard to read, maximum score is 5. You can type your essay and paste in the space.
Rev: 3/22/2016