The Body's Blood Vessels Laid End to End Would Circle the Earth 2.5 Times
The human circulatory system contains a vast network of arteries, veins, and capillaries totalling approximately 100,000 kilometres in length. Laid end to end, they would wrap around the Earth roughly 2.5 times. The capillaries alone account for about 80% of that total length. The walls of capillaries are just one cell thick — allowing oxygen, nutrients, and waste products to pass directly into and out of surrounding tissues.