Download Cardiac Muscle

Name:__________________________ Class: 3_____-______ Homework Due Date:_____________
The Muscular System
There are more than 650 muscles in the human body. Muscles are made of
muscle tissue that work like the elastic material in a rubber band. Thousands or
even tens of thousands, of small fibers make up each muscle.
The three Types of Muscles
All muscles are voluntary or involuntary. Voluntary muscles you can
control. Involuntary muscles work automatically (on their own).
1. Cardiac Muscle – This is your heart muscle. It works on its own, so it is
an example of an involuntary muscle.
2. Smooth Muscles –These muscles work own their own, so they are
examples of involuntary muscles. Examples of smooth muscles are your
stomach and intestines that help you digest your food, or the iris of your
eye.
3. Skeletal Muscles – These are the muscles that attach to your bones.
Tendons attach muscles to bones. When a muscle contracts it pulls on a
tendon to move the bone. These are voluntary muscles.
Cardiac Muscles
Smooth Muscles
Skeletal Muscles
What would happen if your heart was a voluntary muscle?
___________________________________________________________________
___________________________________________________________________
__________________________________________________________________.
What might happen if your skeletal muscles were involuntary?
___________________________________________________________________
___________________________________________________________________
__________________________________________________________________.
1
Homework:
When you woke up this morning, what was the way you used your three different
types of muscles? Write (or type) your answers using complete sentences.
Cardiac muscles?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________.
Smooth muscles?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________.
Skeletal muscles?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________.
2