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Lesson 03 · about 7 minutes

The heart and great vessels

Valves, coronary circulation and the large vessels at the base of the heart, including what this model does not show.

What the model contains

In the source data the heart is one surface, the heart wall, so the four chambers cannot be selected separately. The model also includes three valves, the coronary arteries and cardiac veins, and the large vessels close to the heart. The aortic valve and the superior vena cava are not included.

Valves keep blood moving one way

The tricuspid valve lies between the right atrium and right ventricle; the mitral (bicuspid) valve between the left atrium and left ventricle. The pulmonary valve guards the exit from the right ventricle. Each closes to prevent blood flowing backwards.

Pulmonary and systemic circuits

The right ventricle pumps deoxygenated blood into the pulmonary artery towards the lungs. Oxygenated blood returns through the pulmonary veins to the left atrium. From the left ventricle, blood enters the ascending aorta, curves through the aortic arch and travels down the descending aorta.

The heart muscle receives its own blood supply through the coronary arteries, which branch from the base of the aorta. The cardiac veins drain into the coronary sinus, which empties into the right atrium.

Check your understanding

1. Which vessel carries deoxygenated blood from the right ventricle to the lungs?
2. Which valve lies between the left atrium and the left ventricle?

Further reading

OpenStax Anatomy and Physiology 2e (J. Gordon Betts et al., OpenStax, 2022) is cited as further reading. Its text is licensed CC BY-NC-SA 4.0 and is not reproduced here; SomaVista's explanations are written independently.