GLOSSARY

The systemic circulation, or greater circulation, is the route that carries oxygenated blood from the left heart to all body tissues (except the exchange portion of the lungs) and returns deoxygenated blood to the right heart.

Route

Left ventricle → aortic valve → aorta → arteries → arterioles → tissue capillaries → venules → veins → venae cavae → right atrium.

Characteristics

• High pressure and resistance: mean arterial pressure about 90–100 mmHg.
• Main resistance: in the arterioles, which distribute blood flow between organs by constricting and dilating.
• Blood reservoir: about 60–70 percent of blood volume is in the veins, which are called capacitance vessels.

Distribution of Blood Flow