THE CARDIOVASCULAR SYSTEM: The heart, lungs and blood vessels all work together as a unit! 1. Cardio refers to the heart. Vascular refers to the system of blood vessels. 2. These vessels can be either Veins (bring de-oxygenated blood back to the heart) or Arteries (bring oxygenated blood from the heart to the muscles and organs). 3. Deoxygenated blood enters the heart in the right atrium. Next it is pumped into the right Ventricle. Blood then travels to the lungs to pick up oxygen before it returns to…