What membrane lines the cavities of the heart?

What membrane lines the cavities of the heart?

• A. Endocardium
• B. Epicardium
• C. Parietal Pericardium
• D. Serous Fluid

Answer: (A)

Endocardium is the innermost layer of the heart wall, lining the chambers and covering the heart valves. It provides a smooth, low-friction surface for blood to flow and helps safeguard the inner surfaces from damage. The epicardium is the outer layer that sits on the heart muscle, part of the serous pericardium. The parietal pericardium lines the outer fibrous sac around the heart, and serous fluid is the lubricating liquid between the parietal and visceral (epicardial) layers. So the membrane that lines the cavities of the heart is the endocardium.

Endocardium is the innermost layer of the heart wall, lining the chambers and covering the heart valves. It provides a smooth, low-friction surface for blood to flow and helps safeguard the inner surfaces from damage. The epicardium is the outer layer that sits on the heart muscle, part of the serous pericardium. The parietal pericardium lines the outer fibrous sac around the heart, and serous fluid is the lubricating liquid between the parietal and visceral (epicardial) layers. So the membrane that lines the cavities of the heart is the endocardium.