What Are Blood Vessels?

Blood vessels are intricate networks of hollow tubes that transport blood throughout the entire body.
Types of Blood Vessels

Arteries
Arteries are elastic vessels that transport blood away from the heart.

Veins
Veins are elastic vessels that transport blood to the heart.
Capillaries
Capillaries are extremely small vessels located within the tissues of the body that transport blood from the arteries to the veins.

Sinusoids
Sinusoids are extremely small vessels located within the liver, spleen and bone marrow.

Circulation
Blood vessels carry blood from the heart to all areas of the body. The blood travels from the heart via arteries to smaller arterioles, then to capillaries or sinusoids, to venules, to veins and back to the heart.

Microcirculation deals with the flow of blood from arterioles to capillaries or sinusoids to venules. As the blood moves through the capillaries, substances such as oxygen, carbon dioxide, nutrients and wastes are exchanged between the blood and the fluid that surrounds cells.