Which heart layer lines the interior of the heart chambers?

Which heart layer lines the interior of the heart chambers?

• A. Endocardium
• B. Epicardium
• C. Myocardium
• D. Pericardium

Answer: (A)

The inner lining that lines the interior of the heart chambers is the endocardium. This thin, smooth layer covers all four chambers and also lines the heart valves, providing a low-friction surface for blood to flow and protecting underlying tissues. It’s made largely of endothelium, a type of simple squamous epithelium, with some connective tissue beneath. By contrast, the epicardium is the outer layer covering the heart, the myocardium is the thick muscular layer that contracts to pump blood, and the pericardium is the surrounding sac that encloses the heart. So, the endocardium is the interior lining of the heart chambers.

The inner lining that lines the interior of the heart chambers is the endocardium. This thin, smooth layer covers all four chambers and also lines the heart valves, providing a low-friction surface for blood to flow and protecting underlying tissues. It’s made largely of endothelium, a type of simple squamous epithelium, with some connective tissue beneath. By contrast, the epicardium is the outer layer covering the heart, the myocardium is the thick muscular layer that contracts to pump blood, and the pericardium is the surrounding sac that encloses the heart. So, the endocardium is the interior lining of the heart chambers.