• Fitness & Health
• Sport & Exercise Science
• Physical Education
• Strength & Conditioning
• Sports Medicine
• Sport Management
• Dance

Cardiopulmonary Anatomy

This is an excerpt from Developing Endurance-2nd Edition by NSCA -National Strength & Conditioning Association & Ben Reuter.

The primary anatomical structures of the cardiopulmonary system are the lungs, heart, and capillary beds of the skeletal muscles. We begin our anatomical tour in the lungs. Blood passes through the capillary beds of the lungs, where it unloads carbon dioxide (CO₂) and picks up oxygen (O₂). This oxygen-enriched blood travels from the lungs to the heart via the pulmonary vein. Oxygen-enriched blood initially enters the heart in the left atrium and then flows into the left ventricle. When the heart contracts, or beats, oxygen-enriched blood is ejected from the left ventricle and exits the heart via the aorta. The aorta ultimately branches into several smaller arteries that carry oxygen-enriched blood to the entire body (5, 7, 8).

Once the oxygen-enriched blood reaches, for example, the leg muscles during running, it unloads oxygen and picks up carbon dioxide. Blood exiting the exercising muscles is oxygen reduced and returns to the heart via the venous system. Oxygen-reduced blood is ultimately delivered to the heart via two large veins, the superior and inferior vena cava. The venae cavae deliver oxygen-reduced blood to the right atrium of the heart; the blood then flows into the right ventricle. When the heart contracts, oxygen-reduced blood is ejected by the right ventricle and travels via the pulmonary arteries to the lungs (5, 7, 8).

We have now arrived back at the starting point of our tour of cardiopulmonary anatomy. As the oxygen-reduced blood enters the capillary beds of the lungs, it unloads carbon dioxide and picks up oxygen and then exits the lungs as oxygen-enriched blood via the pulmonary veins (5, 7, 8). This synchrony between the lungs, heart, and tissues occurs constantly, whether the person is awake or asleep. The entire cardiopulmonary system works harder during any endurance-based sporting activity, such as a triathlon.

More Excerpts From Developing Endurance 2nd Edition

---