Types of Blood Vessels in the Body

Blood vessels are the large network of arteries, veins, capillaries and arterioles that make up a part of the circulatory system. The flow of blood is controlled by the heart, but the vessels are the path the blood takes to deliver nutrients to cells. The further from the heart the vessels are located, the smaller in diameter they become to keep a constant pressure.

Arteries

Arteries are the vessels that carry blood away from the heart at the left ventricle. The main artery is the aorta, which spans the body from the heart down to the thighs. Arteries branch into smaller vessels, such as the arterioles, until they reach the capillaries.

Capillaries

Capillaries are the tiniest blood vessels. They are responsible for the actual exchange of nutrients and oxygen at the cellular level. The capillaries deliver the oxygenated red blood cells to the tissues.

Veins

Veins retrieve the de-oxygenated blood and return it to the heart at the right ventricle. The veins are larger vessels that show blue underneath the skin. The bluish color is the color of blood when it loses oxygen elements.

Vital Statistics

Blood vessels are used to take a person's vital statistics of patients. Arteries expand in sync with the heartbeat. The arteries close to the skin-- for example, at the pulse and in the neck--are used to detect a slow or weak heartbeat.

References

• Facts From the Franklin Institute