From the lesson Organ Systems at Work (Science Generation), this fantastic interactive model of a human body lets students see each of the systems separately or together.

Choose from any of the major body systems and read short description on the side.

You can even fade out some systems to see them in the background as you highlight other systems. We have the muscular system faded here, with the cardiovascular system highlighted.

An important part of the body is the heart. The heart is made mostly of muscle and connective tissues. The heart’s primary function is to pump blood. Which level of organization best classifies the heart?

(1) cell

(2) organ

(3) system

(4) tissue

You can find more information here: Become a Better Science Teacher: Teacher Tuneups from SciGen.