HEART AND CIRCULATORY SYSTEM  

                Your blood is your body's transport system.  Its main function is to carry nutrients and oxygen, which provide raw materials and energy to the tissues of your body.  The blood also carries waste away from the tissues and helps maintain body temperature.  To do these things, your blood must circulate continuously.

                Your heart is the center of the circulatory system.  Its steady beating pumps at least five quarts of blood through a full circuit of your body every minute.  The heart consists of two pumps side by side.  The pump on the right side moves blood to your lungs, where waste gasses such as carbon dioxide are removed and oxygen is added.  Freshly oxygenated blood returns to the pump on the left side, which moves it out to the rest of your body.  Blood flows away from the heart through blood vessels called arteries.  These branch many times, and the branches become smaller, forming blood vessels called arterioles.  These too become smaller and branch repeatedly until they are tiny vessels called capillaries.  As the blood moves on through the capillaries, the blood vessels gradually become larger, and eventually become veins.  The veins carry the blood through organs such as the liver, which removes the wastes, and back to the heart.  Then the cycle begins again.

  Atherosclerosis:  If you are healthy, your arteries have walls that are muscular, smooth inside, and elastic enough to accommodate extreme variations in blood pressure, so that blood passes through freely.  Sometimes fatty streaks appear on the inner walls of arteries.  As a fatty streak grows, it further damages the arterial wall.  Eventually it can become a hard mass of fatty tissue that erodes the wall, diminishes the elasticity of the artery, and narrows the passageway and interferes with blood flow.  A large mass is called plaque.  Atherosclerosis is common in North America.  Post mortem examinations of accident victims shows that some degree of the disorder is almost universal, especially in men.  Most people in the Western world eat large amounts of fatty and cholesterol rich foods such as meat, butter and eggs.  Do not wait for symptoms to develop.  By the time they appear, the disease will have been affecting your circulatory system for years.  Change your diet NOW !

  Coronary artery disease: Your heart muscle requires a constant flow of oxygen and nutrient rich blood.  If your coronary arteries become narrowed, they can fail to provide your heart with enough oxygen.  The blood that flows through the arteries may form a clot which can completely block the artery.  When your heart beats faster in response to physical or psychological stress and requires increased oxygen and nutrients, severely narrowed or blocked coronary arteries cannot cope.  The resulting strain causes angina or heart pain.  If the blood flow is severely reduced, you will have a heart attack.  Eat less meat and salt, more fruit and vegetables, and exercise.

  Heart attack:  The most common type of heart attack is caused by blockage of one of the coronary arteries.  The blood supply is cut off to one region of the heart muscle.  Lack of adequate blood supply damages the deprived tissue.  Damage caused by heart attack may weaken and stretch one of the walls of the heart chambers. Dial 911 !!!

  Heart failure:  The pumping action of the heart becomes inefficient.  The most common symptom is breathlessness.  It may gradually become more apparent in the evenings when you are tired.  It may be more difficult to breath when you lie down.  You might experience constant fatigue along with a swelling of the lowest part of your body, from accumulation of fluid.  Reduce physical activities until you can see your doctor.

  High blood pressure:  Too much blood pressure eventually damages your arteries.  The whole circulatory system is under constant strain.  You may experience no symptoms at all, you must have your blood pressure tested.  Left untreated, there are major risks to the heart and brain, and can be fatal.  Don't smoke, limit alcohol consumption, eat a good diet, avoid salt and salt rich foods, try to avoid stress.

  Hardening of the arteries:  As people grow older, their arteries tend to harden. Hardened arteries cannot dilate and constrict to regulate blood flow. This rigidity encourages the formulation of blood clots, which further affects blood flow. Common symptoms can be pain in your calves when your legs are active and disappears when at rest. If your brain is affected, you may get dizzy when you move your head in a certain way, or you may have attacks of temporary loss of vision. Regular exercise has been shown to improve the circulation.

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