My 5 year old son Kulay is already aware that there are other organs in the body other than those that he visibly sees. He is aware that the beating sound in our chest is made by the heart. We would also compare the size of our hearts by comparing the size of our clenched fists.
Kids love to draw simple illustrations of the heart and it is best that they see the heart not just as a representative of love but an essential part of our human body.

Diagram of a Human Heart for Kids: Image taken from Grolier’s Children’s Encyclopedia

Older people and med students are not the only ones who need an illustration of the human heart. Kids also need to have a basic understanding of the different parts of the heart and how the heart works.