Structure of the Human Heart

The heart is a muscular organ located in the upper body (chest area) with the following structural components:

• A ventricular septum separates the left and right side of the heart.
• The right ventricle supplies blood to the lungs, which are close by for oxygenation.
•  The left ventricle can be two to thee times more muscular than the right, due to the need to build up sufficient pressure to overcome the resistance of systemic circulation.
• The muscle of the atria is very thin, due to the fact that these chambers do not create much pressure when pushing blood into the ventricles.
• Coronary arteries lie over the surface of the heart, carrying oxygenated blood to the heart muscle.
• Veins take blood into the atria; arteries take blood from the ventricles.
• The vena cava carries deoxygenated blood into the right atrium. The pulmonary vein carries oxygenated blood into the left atrium. From here, blood flows into the ventricles via the atrioventricular valves. 
• Chordae tendineae attach to the walls of the ventricles and are kept in position by papillary muscles. These tendinous chords prevent inversion of bicuspid and tricuspid valves.
• Valves prevent the backflow of blood. Atrioventricular valves prevent the backflow of blood from the ventricles to the atria. Semilunar valves prevent blood returning to the heart as the ventricles relax.