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Your body has nearly 100,000 miles of blood vessels. Learn how they work, and how you can keep them healthy.

Your vascular system is a vast network of blood vessels that carries blood throughout the body. At first glance, it may seem as though all of your blood vessels are basically the same, transporting blood to and from your body’s tissues. The reality, however, is quite different.

Your body has three types of blood vessels – arteries, veins and capillaries.  Each of the three types is made up of different types of cells (structure). In addition, the three types of blood vessels each perform different jobs (function).

Understanding how arteries, veins and capillaries are different, and how they function as part of the cardiovascular system, can help you understand your vascular health – which can help you avoid cardiovascular disease, stroke and other chronic diseases.

What is an artery, and how does it work?

The job of your arteries is to take oxygen-filled blood from the heart out to the rest of your body. They are under high pressure as each heart beat pushes blood through them. To handle the pressure, the wall of the arteries is strong, thick, and muscular.  

What is a vein, and what is its job?

Whereas arteries take the blood from the heart to the body when it’s full of oxygen, the veins are responsible for the return trip. They take oxygen-depleted blood and send it back to the heart to be re-oxygenated. Unlike arteries, veins form a low-pressure system. Because they are under less pressure, veins have thinner, weaker walls than arteries do.

Veins work against gravity to get the blood back up to the chest. To prevent blood from pooling in, for example, the lower legs and feet, veins have a system of one-way valves that close between heart beats so that blood can’t rush to the lowest point. In contrast, arteries do not have valves.

How do capillaries fit in?

Both arteries and veins are designed to keep blood traveling to and from the heart – but how do the oxygen and nutrients get from the arteries to the body’s cells? And how do the cells get rid of waste products and carbon dioxide? That is where capillaries come in.

Capillaries are the connection between the vascular system and the body’s tissues. Capillary walls are only one cell thick, so that oxygen and nutrients can pass between the blood and the body’s other cells.

If the vascular system were like the U.S. Postal Service, a huge system delivering mail to and from millions of locations, the capillaries would be like the individual mail carriers, bringing letters to each location and taking other letters away.

The Vascular Center at UMMC Midtown Campus provides multidisciplinary care for vascular disease, including diagnosis through our non-invasive vascular laboratory as well as a full range of treatment options, including minimally invasive surgical procedures.

To learn more or make an appointment, call 443-552-2900. To make an appointment for diagnostic imaging in our noninvasive vascular lab, call 410-225-8144.