Muscle Contraction

Art & Research: Sarah J. Lee

Further Reading Literature: John Choo

Have you ever wondered...

How do our muscles contract? Think about it!

Our muscles visibly contract and relax, but these movements occur on a microscopic scale!


Just as a single team-mate is the most basic unit of a sports team, a sarcomere (sahr-co-meer) is the most basic functional unit of a muscle cell.

Abundance of sarcomeres

There are thousands of sarcomeres in one muscle cell! These sarcomeres give muscle its striated appearance.

But, how does this explain how muscles work?

A closer look

Let's take a closer look...

A sarcomere (there muscle) is composed of these two proteins.

Actin and myosin

Actin and myosin must interact, but first they need some help...

Actin and myosin need calcium (Ca2+) and energy (ATP) to be attracted to each other!

Muscle contraction

The actin and myosin proteins slide along each other, causing muscles ([containing] sarcomeres) to contract.

Well, this has been an "exercise" in thinking!

Want to learn more about this topic?

Check out the additional resources below!