Video narration
How does blood get out to your body, then find its way back? Think of it as a delivery loop. Blood returning from your body enters the right side of your heart with carbon dioxide picked up along the way. That side sends it to your lungs. Here, blood releases carbon dioxide and takes in oxygen from the air. But it isn't one straight trip from heart to body. After that pickup, blood returns to the left side of the heart, which pumps it around your body. As blood reaches your tissues, it delivers oxygen for them to use and picks up carbon dioxide. Then it carries that load back to the heart, ready to go again. Your heart sends blood to the lungs for oxygen, then around your body and back to start the delivery loop again.