UNIT 1. BODY SYSTEMS
1. THE CIRCULATORY SYSTEM AND THE HEART
... about the Circulatory system and how it works in conection to the respiratory system. VIDEO.
(Specially from: 2:50 to 4:20 & from: 8:30 to 9:50)
2. THE RESPIRATORY SYSTEM AND THE LUNGS
DO YOU WANT TO LEARN MORE? CLICK ON THE LUNGS
3. THE REPRODUCTIVE SYSTEM
