The Vascular system includes
1) Red arteries that carry oxygen-rich blood away from the heart;
2) Blue veins that carry oxygen-poor blood back to the heart.

Blood exits the left side of the heart and travels through the body. It enters small blood vessels delivering nutrients while collecting waste products and carbon dioxide.

Then, blood travels in veins passing through the Kidneys and liver delivering waste products. Eventually, blood returns to the right side of the heart ready to repeat the process.