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The Cardiovascular System


by Dr. Mary Williams, R.N. D.C.

The heart and the entire circulatory system responsible for moving blood throughout the body are part of the cardiovascular system. As the heart beats in the chest, it pushes blood out through arteries to nourish cells with oxygen and nutrients. Your beating heart also pulls blood back through veins to replenish it with oxygen and nutrients once again. The heart beats about 100,000 times each day to perform its work of moving blood throughout the body.

Facts About the Cardiovascular System

The circulatory system contains two subsystems that work together to make the body function. The systemic circulatory system involves the heart moving blood out to every cell in the body and back to fill it with oxygen and nutrients again. The pulmonary circulatory system involves the heart moving blood back and forth in the lungs to fill the blood with oxygen. At the center of the circulatory system lies the heart, which is the muscle responsible for moving blood continually throughout the body. When your body is active and needs faster blood circulation, your heart beats faster to supply it. When your body is resting and doesn't need fast blood circulation, your heart beats more slowly.

  • Functions of the Circulatory System: Drawings and descriptions of the circulatory system explain how blood flows through mammals.
  • Cardiovascular System I: Heart: A labeled diagram illustrates the heart and its intricate components to explain how the heart works.
  • Human Circulatory System: The circulatory system is responsible for transporting oxygen and nutrients to every part of the body and for transporting deoxygenated blood back to the heart.
  • The Circulatory System: As the center of the circulatory system, the heart is where blood flow originates to supply oxygenated blood to the body. View diagrams of the heart and the circulatory system to understand this process.
  • Where the Heart Is: The heart beats an average of 2.5 billion times during an average lifetime, moving blood throughout the body.
  • Overview of the Vascular System: The circulatory system, also called the vascular system, is made up of arteries, veins, and capillaries that move blood pumped by the heart.
  • The Circulatory System: Watch an animated graphic that shows how the heart moves oxygenated blood out throughout the body and brings deoxygenated blood back to recirculate it.
  • Circulatory System Overview: Hillendale Health provides an overview of the circulatory system, including vocabulary and diagrams of the heart and blood vessels.

How it Works

The heart has four chambers and two distinct halves, each serving a different purpose. The right atrium and right ventricle receive deoxygenated blood returning back to the heart from all over the body. The right ventricle is responsible for moving this blood to the lungs, where it will receive fresh oxygen and nutrients. The left atrium and left ventricle receive this oxygenated blood back from the lungs. The left ventricle is responsible for pushing this blood back out to the cells throughout the body. Blood vessels (arteries and veins) are responsible for carrying blood throughout the body. Arteries carry blood away from the heart, and veins carry blood back to the heart.

  • Map of the Human Heart: PBS shows how the heart functions to pump blood throughout the body with an animated interactive and an overview of heart anatomy and heart facts.
  • Circulatory System: Heart Stations: Explore the differences between arteries and veins in this lesson plan designed to teach students about the circulatory system.
  • Your Cardiovascular System: This article explains the relationships between the heart, the blood stream, and
  • How the Body Works: Watch a video that shows how the circulatory system works, including information about the relationship between the heart and the vast network of blood vessels, veins, and arteries.
  • How the Normal Heart Works: The Children's Hospital of Philadelphia explains how a healthy heart works, and you can watch a video that shows how a healthy heart pumps blood.
  • Anatomy Animations: The Texas Heart Institute offers a collection of anatomy animations to show how the heart supplies blood to the body.
  • Study Guide to Systems of the Body: ACLS.net offers an excellent collection of resources for studying the systems of the humany body including the circulatory, respiratory, muscular and digestive systems.

Maintaining a Healthy System

Just like other muscles in your body, the heart needs continual use and exercise to keep it strong and healthy. Aerobic exercise involves activities that increase the heart rate and breathing rate. Activities such as swimming, running, and biking are examples of aerobic exercise. Engaging in regular aerobic exercise helps make the heart stronger. This helps the heart work more efficiently with the lungs, and it helps it pump blood more efficiently throughout the body. Anaerobic exercise involves strengthening activities, such as lifting weights. Anaerobic exercise does not directly benefit the cardiovascular system. However, it can contribute to overall health because it can help you build muscle and become stronger.