Your heart is a pump that moves blood around your body. This delivery system supplies oxygen and nutrients to all parts of your body, and carries away unwanted carbon dioxide and waste products.
Your heart has two separate sides, but they work together. The right side of the heart receives dark, de-oxygenated blood which has circulated around your body supplying it with what it needs. This gets pumped by the heart to your lungs, where it receives a fresh supply of oxygen and becomes bright red and oxygen-rich again.
The cardiovascular system
This circular movement of blood around the body, pumped by your heart, is called the cardiovascular system (or circulation).
Blood leaves through the left ventricle to the aorta, your body's largest artery. It is almost the diameter of a typical garden hose. The aorta leads to smaller arteries, arterioles, and finally capillaries, which are so small you would need ten of them to match the thickness of a human hair.
The heart's other parts
Like every other living tissue, your heart needs a steady supply of fresh blood. This blood supply comes from coronary arteries that run along its surface carrying oxygen-rich blood to the heart muscle.
The heart's pumping action is a result of the muscle contracting and relaxing repeatedly. The complex signals that produce this are created by a web of nerve tissue that runs through the heart.
Surrounding the heart is a sac called the pericardium.
When it goes wrong
Heart problems can develop for many reasons, or may exist from birth if the heart never developed properly. For example:
- A heart may develop problems if the arteries supplying blood become too narrow or get completely blocked.
- Disease or illness can cause the heart to become enlarged, thickened or stiffened, leaving it unable to work effectively.
- The pumping rythmn of the heart can become irregular