Chapter 14: Bones, Muscles,
and Skin
Section 3: The Muscular
System
p. 482 – p. 486
What types of muscles are
found in the human body?
• Your body has three types of muscle
tissue – skeletal muscle, smooth
muscle and cardiac muscle.
• Some of these muscle tissues are
voluntary and some are involuntary.
– Skeletal or striated muscle are voluntary
muscles.
– Cardiac muscles are involuntary muscles.
– Smooth muscles are involuntary muscles.
Why do skeletal muscles work
in pairs?
• Skeletal muscles must work in pairs
because they can only contract. While
one muscle contracts the partner
muscle relaxes or extends to its
original length.
Involuntary Muscle
• Muscles that are not
under your conscious
control.
• They are responsible
for such important
activities as
breathing, heartbeat,
an digesting food.
• Examples are smooth
and cardiac muscles.
Voluntary Muscles
• Muscles that are
under your
conscious control,
like smiling or
turning a page in
your book.
Skeletal Muscles
• Are voluntary
muscles that are
attached to the
bones of your
skeleton and
provide the force
that moves your
bones.
Tendon
• A strong connective
tissue that attaches
muscles to bone.
Striated Muscle
• Skeletal muscle
cells appear to be
banded, or striated.
For this reason,
skeletal muscle is
sometimes called
striated muscle.
Smooth Muscle
• The muscles that are
inside of many internal
organs, such as the
stomach and blood
vessels.
• They work
automatically to
control certain
movements in your
body.
• They are involuntary,
which means you have
no control of them.
Cardiac Muscle
• Cardiac muscle
tissue is found only
in the heart.
• It is involuntary.
• Cardiac muscle
tissue is also is also
striated. Yet it does
not ever get tired
like skeletal muscle
tissue does.
Muscle At Work
• Because muscle cells can only
contract, not extend, skeletal muscles
must work in pairs.
• While one muscle contracts, the other
muscle in the pair relaxes to its
original length.
Do you have any
tape..? Because
I’m ripped!