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.
1966
1946
2012
1976
2022
1992
2020
1961
2024
1969
1968
2019
1981
—
2016
1953
2023
2015
1986