The Pumping Heart
This activity teaches:
1. The size of the heart and what it looks like
2. How the heart pumps
3. Blood vessels are tubes
4. Blood does not continuously flow through the vessels, but moves with the beat of the heart.
All you need is a straw and a red pipe cleaner. A clear straw is preferred (found on amazon) because blood vessels are translucent, but you can also use a pink straw.
Show your child a picture of a heart. Tell him that it's about the size of your fist.
Pretend with your child that your fists are hearts that are pumping. Practice squeezing your fists while mimicking the heartbeat rhythm, pa-pum pa-pum pa-pum.
Now have your child hold the end of the pipe cleaner with his heart-fist and push it through the blood vessel (straw) while pumping. Kids enjoy "threading" the pipe cleaner through a straw (a fine motor skill) and watching as the straw turns from clear to red. If possible, have him push only when he pumps. This takes some coordination, so he might need assistance.