Britannica Sources used in this answer

How does the heart pump blood through systemic circulation?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Vintage anatomy chart showing front and back views of the human skeletal system and muscular system, with detailed illustrations of bones and muscles. — human body Vintage anatomy charts of the human body showing the skeletal and muscle systems.

Systemic circulation is the process by which the heart delivers oxygenated blood to the body's tissues and returns oxygen-depleted blood to the heart. This cycle is driven by the pressure generated from the heart's pumping action.1

The process begins when the left ventricle contracts, forcing oxygenated blood through the aortic valve and into the aorta, the body's largest artery. From the aorta, the blood travels through a branching network of arteries and smaller arterioles to reach the capillaries. At the capillary level, essential substances—including oxygen, nutrients, and hormones—are exchanged with surrounding tissues, while metabolic waste products like carbon dioxide enter the bloodstream.12

Finally, the deoxygenated blood flows into venules and veins, eventually returning to the heart via the superior and inferior venae cavae, which empty into the right atrium. Throughout this process, heart valves ensure that blood flows in only one direction.12