Why does the heart start beating faster?

The heart starts beating faster when your body needs more energy, just like a toy car speeds up when you push it harder.

Imagine your heart is like a little pump that sends blood all around your body. When you run, play, or get excited, your body wants more oxygen and food to keep going, so the heart beats faster, sending more blood quicker than usual.

Your body uses special messengers called signals to tell the heart what to do. These signals are like messages sent through wires in a toy phone, when you get excited, your brain sends a quick message down to the heart: “Go faster!”

Sometimes, like when you're scared or surprised, your body might even send an extra strong signal that makes the heart beat really fast, just like how a toy car zooms forward if you push it really hard.

The more active you are, the more messages the heart gets, and the faster it beats!