Which layers make up the heart?

The layers of the heart are composed of the epicardium, myocardium, and endocardium. The epicardium is the outermost layer, serving as a protective layer and also housing blood vessels and nerves that supply the heart. The myocardium is the thick muscle layer responsible for the heart's ability to contract and pump blood throughout the body. Lastly, the endocardium is the innermost layer that lines the chambers of the heart and covers the heart valves, helping to maintain a smooth surface for blood circulation.

Understanding the structure of the heart is crucial for recognizing how each layer functions in maintaining the heart's overall health and efficiency. The correct choice encapsulates all three essential layers without including any extraneous elements that do not pertain specifically to the makeup of the heart itself.