Heart Anatomy

There are four cavities in the human heart that fill with blood. The top two are called atria, the bottom two are called ventricles. The left ventricle contracts the hardest so this is why the heart can be felt pumping most clearly on the left side of the chest. The septum separates the right and left sides of the heart. A valve connects each atrium to it's corresponding ventricle. The left valve is called the mitral valve and the right valve is called the tricuspid valve. The top of the heart connects to some large blood vessels including the aorta, which carries blood away from the heart and the pulmonary artery that the connects the heart with the lungs. Veins carry blood into the heart, the largest being the superior and inferior vena cava.

The heart is an efficient pump that does not usually stop until death. It is strong and the cardiac muscle contracts and relaxes 70 to 80 times per minute to push blood through the chambers and into the vessels. During exercise the heart pumps more quickly and slows while relaxing. It is small and located in the middle of the chest between the lungs. It is protected by the breastbone and diaphragm and rests in a chamber called the pericardial cavity that is surrounded by the ribcage.

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