On a recent Sunday in Sunbeams (Sunday School class for 3 year olds), apparently they talked about their bodies and how they're created by Heavenly Father. So they were told to draw their bodies.
Quartus drew this. It's his "blood stream" (circulatory system.) The red and blue lines are the veins and arteries. And that bow-tie looking thing is the heart.
It makes me so happy when the kids look like little nerds! He learned about this stuff from a Leap TV game called, "The Human Body Game." Best $3 (on sale and with a coupon) that I've ever spent!