Located between the lungs plays an important role in the development of the immune system of the body.

Involves blood flow to all parts of the body except the lungs. The oxygen-rich blood flows out of the heart from the left ventricle into arterial circulation. It returns to the heart as oxygen-poor venous blood and flows into the right atrium.

Involves the flow of blood out of the heart from the right ventricle and through the pulmonary arterial system. In the lungs, waste material (carbon dioxide) is exchanged for oxygen. The pulmonary venous system carries the oxygen-rich blood into the left atrium of the heart.

Large blood vessels that carry oxygen-rich blood away from the heart to all regions of the body. Arterial blood is bright red in color.  The aorta is the largest artery.

Smaller branches of arteries. They are thinner than arteries and carry the blood to the capillaries.

Measurement of the amount of pressure exerted against the walls of the blood vessels. Normal BP is 120/80 in adults. BP is measured by a sphygmomanometer.

ventricles relax, causing lowest pressure against the arterial walls.

ventricles contract causing the highest pressure against the arterial walls. This is the 120 (higher level) of the 120/80.

Composed of 55% liquid plasma and 45% formed elements. Most blood cells originate in the marrow cavity of bones.

Microscopic vessels only one epithelial cell in thickness (similar in thickness to a strand of hair). The slower blood flow though capillaries allows time for the exchange of oxygen, nutrients and waste materials between the tissue fluids and the surrounding cells.

Red blood cells containing hemoglobin, a blood protein that helps transport oxygen throughout the body. RBC 's make up about 45% of the blood. They live for approximately 120 days. Two - 10 million RBC's are destroyed each second, but because they are constantly being replaced, the number of circulating cells remain constant.

Leukocytes

White blood cells that help fight disease.

Straw-colored fluid that transports nutrients, hormones and waste products. Plasma is 91% water, remaining 9% clotting proteins.

Rhythmic expansion and contraction of an artery produced by the pressure of the blood moving through the artery.

Antigen present in the blood of most people. A person having this is Rh+, someone lacking the antigen is Rh-.

Plasma with the clotting proteins removed.

Known as the "natural pacemaker", found in the right atrium of the heart. It establishes the basic rhythm of the heart.

Form a low-pressure collecting system to return the oxygen-depleted, waste-filled blood to the heart. The largest veins are the venae cavae (superior vena cava drains from upper portion of the body and the inferior vena cava drains from the lowert portion of the body), both draining into the right atrium of the heart.

A reduction in the number of circulating red blood cells

Localized balloon-like enlargement of an artery.

Left-sided chest pain due to nadequate blood and oxygenation of the heart muscle.

Narrowing of a blood vessel.

Irregularity of heart rhythm.

Plaque formation (fatty deposit) within the arterial wall.

Hardening and narrowing of the arteries due to a buildup of plaque formation.

Coronary artery disease - atherosclerosis of the coronary arteries.

Pain and weakness in the leg when walking, due to peripheral vascular disease.

Small holes in the septa between the atria and ventricles.

Congestive heart failure - inability of the heart to circulate blood effectively enough to meet the body's needs.

Rapid, random and ineffective contractions of the heart (350 beats or more per minute).

Cardiac arrhythmia in which the atrial contractions are rapid but regular (may reach up to 300 beats per minute).

An abnormal heart sound caused by improper closure of a heart valve.

Localized area of necrosis (death of tissue) caused by interruption of blood supply.

Deficiency of blood supply due to constriction or obstruction of a blood vessel.

Myocardial infarction or heart attack - occlusion (blockage) of a coronary artery resulting in an infarct of the affected myocardium.

Abnormal narrowing of the opening of the mitral valve.

MVP

Mitral valve prolapse - abnormal protrusion of the mitral valve that results in incomplete closure of the valve.

Electronic device implanted under the skin to regulate heartbeat.

Pounding or racing heart with or without irregularity in rhythm.

Inflammation of the membrane (pericardium) surrounding the heart.

Small pinpoint hemorrhages found under the surface of the skin.

Abnormally swollen veins usually occurring in the leg.

Dye is injected into the bloodstream or heart chamber and x-rays are taken of the heart and large blood vessels in the chest.

Listening to sounds within the body with a stethoscope.

Coronary Artery Bypass Graft - vessels are connected to existing coronary arteries to detour around blocked vessels.

Magnetic waves are beamed at the heart and an image is produced.

Scan of the heart measuring the accumulation of radioactive substance injected into the heart.

Cardiac catheterization of the heart - a thin flexible tube is introduced into a vein or artery and guided to the heart to detect pressures and patterns of blood flow.

Known as cardioversion - use of electrical shock to restore the heart's normal rhythm.

Digital subtraction angiography - x-ray pictures of the blood vessels are taken.

Electrocardiogram - record of the electrical activity of the heart.

Echocardiography - sound waves are transmitted into the chest and echoes returning from the valves, chambers and surfaces of the heart are electronically plotted and recorded.

Device to monitor the heart for 24 hours with a portable electrocardiograph.

Measurement of fatty substances found in foods and in the body.

Enzymes are measured for patient's who have had an MI.

Exercise tolerance test to determine the heart's response to physical exertion.