What is the Vascular System?

The human body has two circulatory systems–the cardiovascular (vascular) system and the lymphatic system.  The center of our attention here will be on the vascular system.

So, just what is the vascular system?  Simply put, the vascular system is a system of vessels with a vessel being defined as a hollow tube for carrying something.  Blood vessels, therefore, are hollow tubes for carrying blood and are located throughout your body.  There are three varieties of blood vessels:

  1. Arteries that carry blood away from the heart
  2. Capillaries that pass blood from the arteries to the veins
  3. Veins that carry the blood back to the heart

Since our interest here will be the arteries and the veins, let us first take a look  at some amazing, well-known but little discussed facts at just how vast all these vessels are and, hopefully, gain a full appreciation of just how hard the heart and the muscles work to keep blood moving throughout our body.  Understanding the difficult work the heart and muscles do and how you can help them with that work will be important in many things that one can do to prevent or slow down problems related to the vessels.

There are over 60,000 miles of blood vessels in a child’s body and close to 100,000 miles in the body of an adult.  Think of it this way–the circumference of the earth at the equator is 25,000 miles so if the blood vessels of an adult were lined up end to end, they would circle the equator four times!  Now remember, blood vessels include arteries, veins and capillaries and most of the blood vessels in the human body are the smaller capillaries but there are a lot of them.  When you consider these numbers, it is almost too much to imagine that this vast network is housed within the confine of our own body.  So with that new appreciation, let us move on with our discussion of the arteries and the veins.

Basically, the arteries carry oxygen-rich blood from your heart to every part of the body, including the brain, intestines, kidneys, arms, legs and the heart itself.  A problem in the arteries is called arterial disease.  The veins return oxygen-poor blood to your heart from all parts of the body and a problem in the veins is called venous disease

As the blood travels through the arteries, it enters smaller and smaller blood vessels reaching every cell in the body, dropping off nutrients and picking up waste products and carbon dioxide.  The blood then starts the trip back in the veins entering larger and larger vessels as it goes, passing through the liver on the way to drop off waste products.  The blood eventually arrives back at the right side of the heart to start the trip all over again.

The smallest vessels of the vascular system are the capillaries.  These are the tiny blood vessels between the arteries and the veins. 

The second circulatory system is the lymphatic system.  Lymph helps to protect and maintain the fluid environment outside the body cells.  Lymph vessels drain lymph fluid back to one or two major veins at the base of the neck and back to the veins and then the arterial circulatory system.  These channels return 1.5 to 2.5 liters of fluid per day to the vein or veins at the base of the neck.  Lymph flows in only one direction.  Lymph is a clear to slightly yellow liquid that contains waste.

Again, our further focus and discussions here will be primarily on the arteries and veins, but we will have some discussion later of what can occur when you have a problem in your lymphatic system (lymphedema).


We hope the information on these pages is both informative and helpful, but it is intended for education only.  Please do note that no web site, no matter how much information is shared, can replace a consultation with your doctor and a vascular specialist.  Medical technology and treatment are continually improving and evolving so before making any decision on treatment, it is always advisable to see your doctor first for a comprehensive evaluation of your vascular disease and other medical conditions.

At the Vascular Center of Wichita Falls, we work closely with your other physicians.  If you have concerns about your arteries or veins, contact us.  A referral is not necessary to make an appointment.