Your body is full of muscles -- about half your body weight is muscle! You use your muscles for every move you make; they pull your bones every which way. They are the engines that make your body go; the forces that create movement. When these muscles work, they are in the process of getting shorter, or contracting.
Muscles not only contract to create motion when you decide to do something like raising your arms or legs. They are also busy moving food through your stomach and blood through your vessels -- when you aren't even thinking about them. That's because there are different kinds of muscles based on the functions they perform. All your 650 muscles can be classified into three different kinds:
1. Skeletal muscles move your bones.
2. Smooth muscles move your organs and vessels.
3. Cardiac muscles make your heart beat.
Muscles of three types you'll find
Skeletal, smooth, and the cardiac kind
Skeletal muscles come in pairs
With the bones you¹ll find them there
Workin¹ together to make you strong
One gets short while the other long
Like your arm when muscles flex
Biceps short and long triceps
Chorus:
Your heart is a muscle too
Skeletal type working like a smooth
A specialized muscle called the cardiac
But your skeletal muscles go right up your back
If you¹ve ever navigated on the Erie Canal
Voluntary muscles all
Striated, the skeletal
Tendons at the bones connect
With the joints so they can flex
Involuntary are the kind
That move with no choice from your mind
Like your stomach with muscles smooth
And in the walls of blood vessels too
