The blood vessels are part of the circulatory system and function to transport blood throughout the body.

Types

• Arteries
  • Aorta (the largest artery, carries blood out of the heart)
• Arterioles
• Capillaries (the smallest blood vessels)
• Venules
• Veins
  • Venae cavae (the 2 largest veins, carry blood into the heart)

Glossary

• Vasoconstriction is when blood vessels constrict (become narrower, smaller in cross-sectional area) by contracting the vascular smooth muscle in the vessel walls.
  • A vasoconstrictor is any drug that acts to constrict blood vessels. Many vasoconstrictors act on specific receptors, such as vasopressin receptors or adrenoreceptors.

Vasoconstrictors are used to increase blood pressure or to reduce local blood flow.

• Vasodilation is when blood vessels dilate (become wider) by relaxing the smooth muscle in the vessel walls.
  • Vasodilators are drugs that work to dilate blood vessels.

See also

• anatomy
• human anatomy
• cardiovascular system
• vascular resistance
• endothelium
• endothelium-derived relaxing factor
• anastomosis
• atherosclerosis
• vasculitis (inflammation of blood vessels)
• angiogenesis (formation of blood vessels)

Cardiovascular system

Heart - Aorta - Arteries - Arterioles - Capillaries - Venules - Veins - Venae cavae - Pulmonary arteries - Lungs - Pulmonary veins - Blood