Overview of the Vascular System
What is the vascular system?
The vascular system is made up of the vessels that carry blood and lymph fluid through
the body. It's also called the circulatory system. The arteries and veins carry blood
all over the body. They send oxygen and nutrients to the body tissues. And they take
away tissue waste. The lymph vessels carry lymphatic fluid. This is a clear, colorless
fluid made of water and blood cells. The lymphatic system is part of the immune system
that helps rid the body of toxins and waste. It does this by filtering and draining
lymph away from each region of the body.
The vessels of the blood circulatory system are:
Arteries. These are blood vessels that carry oxygenated blood away from the heart to the body.
Veins. These are blood vessels that carry blood from the body back into the heart.
Capillaries. These are tiny blood vessels between arteries and veins that distribute oxygen-rich
blood to the body.
When the heart pumps, blood moves through the circulatory system. Blood leaving the
heart through the arteries is full of oxygen. The arteries branch off into smaller
and smaller tubes. These bring oxygen and other nutrients to the cells of the body's
tissues and organs. The smallest tubes are called capillaries. As blood moves through
the capillaries, the oxygen and other nutrients move out into the cells. Then waste
matter from the cells goes into the capillaries. As the blood leaves the capillaries,
it moves through the veins. Veins merge into larger tubes to carry the blood back
to the heart.
The vascular system is also an important part of other body systems. Examples include:
Respiratory system. As blood flows through the capillaries in the lungs, carbon dioxide is removed and
oxygen is picked up. The carbon dioxide leaves the body through the lungs. And the
oxygen is sent to the body tissues by the blood.
Digestive system. As food is digested, blood flows through the capillaries in the intestines. These
tubes pick up nutrients. These include glucose (sugar), vitamins, and minerals. These
nutrients are sent to the body tissues by the blood.
Kidneys and urinary system. Waste materials from the body tissues are filtered out from the blood as it flows
through the kidneys. The waste then leaves the body in the form of urine.
Temperature control. Control of the body's temperature is helped by the flow of blood in the different
parts of the body. Heat is made by the body's tissues. This happens as they break
down nutrients for energy, make new tissue, and give up waste matter.
What is vascular disease?
A vascular disease is a condition that affects the arteries and veins. Most often,
a vascular disease affects blood flow. It may do this by blocking or weakening blood
vessels. Or it may do this by causing damage to the valves that are in veins. Organs
and other body areas may be harmed by vascular disease due to partly or fully blocked
What causes vascular disease?
Causes of vascular disease include:
Atherosclerosis. This is a buildup of plaque. Plaque is a deposit of fatty substances, cholesterol,
cell waste, calcium, and fibrin. It can build up in the inner lining of an artery.
It's the most common cause of vascular disease. It's not known how atherosclerosis
starts or what causes it. It's a slow, ongoing disease that gets worse over time.
It may start as early as childhood. But the disease can also get worse quickly. It
causes the buildup of fatty deposits along the innermost layer of the arteries. This
thickening narrows the arteries. It can lessen or fully block the flow of blood to
organs and other body tissues.
Blood clots. A blood vessel may be blocked by an embolus. This is a tiny mass of debris that moves
through the bloodstream. Or it may be blocked by a thrombus. This is a blood clot.
Inflammation. In general, inflammation of blood vessels is referred to as vasculitis. This includes
a range of disorders. Inflammation may lead to narrowing and blockage of blood vessels.
Injury. Injury of the blood vessels may lead to inflammation or infection. This can damage
the blood vessels and lead to narrowing and blockage.
Genetic. Some conditions of the vascular system are inherited.
What are the effects of vascular disease?
The functions of the blood vessels include supplying all organs and tissues of the
body with oxygen and nutrients. They include removing waste products, fluid balance,
and other functions. Because of all these functions, conditions that affect the vascular
system may affect the part(s) of the body supplied by a certain vascular network.
Examples of the effects of vascular disease include:
Coronary artery disease. This can cause heart attack or angina (chest pain).
Cerebrovascular disease. This can cause stroke or transient ischemic attack (TIA). TIA is a short-term loss
of blood flow to an area of the brain. It usually last less than 5 minutes but not
longer than 24 hours, with complete recovery.
Peripheral arterial disease. This may cause claudication. This is pain in the thigh, calf, or buttocks that occurs
when walking. It can also cause critical limb ischemia. This is lack of blood supply
and oxygen to the limb or leg at rest.
Vascular disease of the great vessels. This can cause an aortic aneurysm. This is a bulging, weakened area in the wall of
a blood vessel due to an abnormal widening or ballooning. It can also cause coarctation
of the aorta. This is narrowing of the aorta, the largest artery in the body. It can
also cause Takayasu arteritis. This is a rare inflammatory disease that affects the
aorta and its branches.
Thoracic vascular disease. It can cause thoracic aortic aneurysm. This is a bulging, weakened area in the wall
of a blood vessel. It causes an abnormal widening or ballooning in the chest (thoracic)
part of the aorta.
Abdominal vascular disease. It can cause an abdominal aortic aneurysm. This is a bulging, weakened area in the
wall of a blood vessel. It causes an abnormal widening or ballooning in the belly
(abdominal) part of the aorta.
Peripheral venous disease. This can cause deep vein thrombosis (DVT). DVT is a blood clot in a deep vein in
the muscles of the leg. This disease can also cause varicose veins.
Lymphatic vascular diseases. These can cause lymphedema. This is swelling caused by problems of the normal draining
of the lymph nodes.
Vascular diseases of the lungs. These can cause granulomatosis with polyangiitis. This is an uncommon disease in
which the blood vessels are inflamed. It mainly affects the respiratory tract and
the kidneys. Other diseases include angiitis (inflammation of blood vessels) and hypertensive
pulmonary vascular disease. This is high blood pressure in the lungs' blood flow.
Renal (kidney) vascular diseases. These can cause renal artery stenosis (blockage of a renal artery). They can also
cause fibromuscular dysplasia. This is a condition that weakens the walls of medium-sized
arteries. It occurs most often in young women of childbearing age.
Genitourinary vascular diseases. These can cause vascular erectile dysfunction (impotence).
Vascular diseases may affect more than 1 of the body's systems at a time. Because
of this, many types of doctors treat vascular problems. Specialists in vascular medicine
or surgery work closely with doctors in other specialties. These include doctors of
internal medicine, interventional radiology, cardiology, and others.