What my teacher did, for us, in the 3rd grade was she got us all white tee-shirts and drew our organs on it like the outline of the coloring book. Heart, Lungs, Liver, Stomach, intestines, and bladder. She put the kidneys on the back. She would give us clothing paint and a sponge and she started at the heart and what it does and what nutrients the heart takes. when she was done giving us some pointers on that she told us to color it red, because it was read.
Then she went on to the lungs and explained what they were for and what ways to stay healthy to breath right and the different nutrients that help with lung health. Then she had us paint them like a deep pink color.
Then the liver- when she was done teaching us and asking us questions to see what we remember she had us paint it a purplish red color.
The stomach- she had us paint yellow.
Intestines- she had us paint a deep pink for the large and light pink for the soft and explained why we have two sets. The small absorbed all the nutrient and the large absorbed water and got rid of the waste.
The bladder she had us paint a light gray and said the different nutrients to take to maintain a healthy bladder like cranberry juice.
The kidneys- she said that water is the best thing for them, they run like the filters in your body and it is good to always flush them out. That fact is still true today. We painted them a purplish red.
It was a cool idea and when it dried we could wear the tee-shirts. It was actually pretty cool. My teacher was cool like that. to this day, I still remember what she taught me, despite being a bio-major, I still remember what she, herself, taught me about my vital organs. What I know now is just them in more detail being a radiologic technologist/ student.