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.
2016
2021
1971
2022
2009
1972
1967
2012
2013
1985
1988
2019
1930
1960
2017
2015
1968