Sydän Kids Health Your Heart and Ciculatory System Kids Health: Your Heart and Circulatory System heartbeat the heart and circulatory system KIDS HEALTH this article heart this article https://kidshealth.org/en/kids/heart.html Kids Health: Your Heart and Circulatory System Your Heart and Ciculatory System KidsHealth: Your Heart & Circulatory System https://kidshealth.org/en/kids/heart.html article on the heart KidsHealth: Your Heart & Circulatory System