A young boy learns about his heart through the step-by-step construction of a simple circulatory system. He learns how his heart pumps, what blood and blood vessels do, how they do it, and some of the ways to help his heart stay healthy.
1962
2017
2006
1953
2019
1983
1979
2012
1941
1966
2001
1972
1948
1963
1958
2021