Something Learned from My Son

I'm spending the weekend with my kids (9 and 7 year olds :-)) In between the biking, visiting the aquarium, shopping and cooking (three hour beef stewing making! And yes in the middle of the Florida heat), I learned from my son that human bodies have these systems:

Skeletal - bones

Muscular - muscles

Nervous - nerves

Circulatory - blood

Respiratory - breathing

Digestive - nutrients and "poop"

Immune - defense

Endocrine - hormones

Integumentary - hair, skin and nails

Urinary - "pee"

Reproductive - "making babies"

Also learned this: