LO2: Identify the three layers of the heart wall and the tissues which make up these layers

What are the three layers of the heart wall (outermost to innermost)?

Epicardium, myocardium, endocardium.

What tissue makes up the epicardium?

Epithelial and connective tissue — it is a serous membrane (also called the visceral pericardium).

What tissue makes up the myocardium?

Cardiac muscle tissue – it is the thick, muscular, contractile layer.

What tissue makes up the endocardium?

Simple squamous epithelium – a smooth lining inside the heart chambers and valves.

What is the function of the epicardium?

Protects the outer surface and reduces friction during heartbeats.

What is the function of the myocardium?

Contracts to pump blood – it’s the working muscle layer of the heart.

What is the function of the endocardium?

Provides a smooth surface to reduce resistance and protect inner heart surfaces.

What is the difference between the visceral and parietal pleura?

The visceral pleura is the inner membrane lining the lungs; the parietal pleura lines the chest wall.

Which heart layer is the thickest and why?

The myocardium, because it contains cardiac muscle tissue that contracts to pump blood.

Where is the endocardium located?

It lines the inner surfaces of the heart chambers and covers the heart valves.

What is the relationship between the epicardium and the pericardium?

The epicardium is the visceral layer of the serous pericardium and lies directly on the heart surface.