The atria (plural for atrium) are two chambers found in the heart. The right atrium is positioned between two vena cavae, and it has extremely thin walls. It is connected to the right ventricle and is located above it. The left atrium is hidden in front by the pulmonary artery and aorta. Its walls are thicker than the right atrium. Both atria have a smooth inner surface.
|You will see this labeled illustration in many places across the site. Click on any of the labels for a description of the specific part.||
Check out the Clickable Heart to see the different parts of the heart.