Human Heart Structure & Parts

Human heart

Heart is the muscular organ responsible for pumping of blood in all over the body of human being through blood vessels by repeated contraction of human heart.

Structure

Heart is located in the chest cavity. It is enclosed in a double membranous sac which is called pericardial cavity. The pericardial cavity contain the fluid called pericardial fluid, between pericardium and heart wall. The pericardial fluid protects the heart from friction because when heart contract or extract the friction is produced. The term cardiac means “related to the heart”. The bulk of the walls of heart chambers is made of cardiac muscle.in human body heart is situated between lungs in the middle of chest cavity. The human usually felt that the heart is to be on the left side. Because left chamber of heart i.e. left ventricle is stronger and slightly bigger then the right chamber of heart.

Human heart consist of four chambers, like other animals. the upper thin walled chambers are called left and right atria. And lower thick walled chambers are called left and right ventricles. Human hearty work as a double pump because it receives deoxygenated blood from body and pumps it to lungs. At the same time, it receives oxygenated blood from lungs and pump it to all part of body.

The wall of the heart is composed of three layers

1. Epicardium
2. Myocardium
3. Endocardium

Myocardium of the heart is made up of special type of muscles, the cardiac muscles. These muscles contain myofibrils and myofilaments of myosin and actin. Their arrangement is similar to those in skeletal muscle fibers and their mechanism of contraction is essential the same, except that they are branched cells, in which the successive cells are separated by junctions called intercalated discs.

Parts of Heart

1. There are following parts of human heart;
2. Aorta
3. Superior vena cava
4. Pulmonary artery (to right lung)
5. Pulmonary veins (from right lung)
6. Right atrium
7. Atrioventricular valve(tricuspid)
8. Inferior vena cava
9. Right ventricle
10. Descending aorta (to lower body)
11. Heart muscle
12. Ventricular septum
13. Left ventricle
14. Atrioventricular valve(bicuspid)
15. Pulmonary veins (from left lung)
16. Semilunar valves
17. Left atrium
18. Pulmonary artery (to left lung)