Muscles

A muscle is a soft and elastic organ that  produces movement.  There are 600 muscles in our bodies.

They are connected to the bones and move them by contracting and relaxing.
When muscles contract they get shorter,  but when they relax they get longer.

There are two types:

- Voluntary muscles: when we want to move them, our brain sends a signal to the muscles (biceps to flex the arm).

- Involuntary muscles: when we cannot control them and
they move by themselves automatically (organs like the heart).

How much do you know about muscles?

How many muscles can you remember?