Which parts comprise the left side of the heart?

The left side of the heart is primarily responsible for receiving oxygenated blood from the lungs and pumping it out to the rest of the body. It comprises the left atrium and the left ventricle, with the mitral valve acting as a critical structure that allows blood to flow from the left atrium to the left ventricle while preventing backflow into the atrium.

The left atrium receives oxygen-rich blood from the pulmonary veins and then passes this blood through the mitral valve into the left ventricle. The left ventricle is the strongest chamber of the heart; it pumps this oxygenated blood into the aorta, from where it is distributed throughout the body.

The inclusion of the mitral valve in the answer accurately reflects its role in the structure and function of the left side of the heart, making it essential to the correct understanding of this part of the cardiovascular system. This well-defined structure ensures effective blood flow within the heart, highlighting its importance in maintaining proper circulation.