The blood in your body travels through an immensely large network of blood vessels called your vascular system. The vascular system is responsible for delivering oxygen and nutrients to and carrying waste products away from all the body’s tissues. It’s over 60,000 miles long and is made up of three main types of vessels: Arteries, capillaries and veins.
Arteries carry oxygen and nutrient-rich blood away from the heart to all of the body’s tissues. The heart pumps the arterial blood rhythmically, giving the arteries a pulse you can feel externally. The arteries branch several times as they reach into every millimeter of your body; as they do, they get smaller and smaller and eventually become capillaries.
Capillaries are the tiny vessels that connect arteries to veins. They have very thin walls that allow the arterial blood’s oxygen and nutrients to pass through and be delivered into the body’s cells. They also take in waste products like carbon dioxide from the body’s cells and carry it into the venous system.
Veins carry the deoxygenated blood and waste from the body’s tissues back to the heart and into the lungs. Once the venous blood reaches our lungs, the waste is expelled out of our body through exhalation and then reoxygenated again upon inhalation. The oxygenated blood is then directed back to the heart where it’s pumped back into the arterial system, starting the whole process over again.
Next time you prick your finger and spill a drop of blood, think about the journey that drop of blood has been on! You may even want to thank it for working so hard and traveling so far, just for you. What a commute it’s had.