Primary Function of the Heart
The human heart is the most vital organ of the body as it is responsible for the blood circulation to all body tissues and organs. Its main functions are: 1) carrying deoxygenated blood from the different tissues and organs towards the heart for oxygenation in the lungs and 2) pumping oxygenated blood coming from the lungs to the different body tissues and organs.
The heart diagram below shows you a detailed view of the different structures of the heart wall.
Structure of the Heart Wall
As you can observe in the heart diagram above, the heart wall is made up of 3 layers namely: the endocardium, the myocardium and the epicardium. Let us examine the structure of each of these heart walls.
- Endocardium. The endocardium (see the heart diagram here) is the innermost layer of the heart which is thin and smooth. It is made up of squamous endothelium layer which makes it smooth. The reason why this layer of heart wall is smooth is to prevent the blood inside the heart from clumping together and forming heart clots. This condition (clotting of blood in the heart) is prevented because it is a very deadly phenomenon.
- Myocardium. The myocardium is the middle layer of the heart wall composed mainly of cardiac muscle tissue. It is the thickest and the strongest part of the heart wall because it is the one responsible for the pumping of the blood to the different body parts.
- Epicardium. The epicardium, as show in the HEART DIAGRAM above, is the outermost part of the heart wall. It is the second thickest heart wall following the myocardium. It is made up of thin layers of serous membranes which help lubricate and protect the outer part of the heart.