Lily was enjoying her day at the playground. She was using all her strong muscles to climb up and down the playset.

Lily's friend George was climbing the monkey bars!

As George made his way across, Lily wondered, how is it that our muscles can allow us to do such fun things?

"Mom! Mom! MOM! How is it that George can climb across the monkey bars using his muscles without falling?"

Lily runs over to her mother excited with lots of questions.

It just so happens that Lily's mother was the right person for this question. Lily's mom is a Registered Nurse and knows all about how the muscles can contract in your body to cause movement.

"Well, Lily, there are a lot of reasons why your muscles don't give out while you are doing these activities. Firstly, your muscles don't function just on their own. Your brain which has what is called your nervous system which sends signals to your muscles by neurons."

"What are neurons? They tell my body what to do? That's silly!"

"Lily, let's try to stick to one topic at a time, you wanted to know how muscles contract, so all you need to know is they send signals from the brain for now."

"Okay! Sorry mom continue."