Circulatory System

• Blood is made up of red blood cells, white blood cells, plasma and platelets
• Red blood cells contain a red pigment called haemoglobin which carries oxygen around the body
• White blood cells are large with a nucleus and defend the body against pathogens
• Platelets are fragments of cells that clot the blood to prevent bleeding and blood loss
• Plasma carries dissolved substances such as carbon dioxide, glucose and hormones
• Arteries have thick muscle walls because they carry blood at high pressure away from the heart
• Veins have thin muscle walls because they carry blood at low pressure back to the heart. There are also valves to prevent backflow of blood
• Capillaries have thin walls which are one cell thick to allow for easy diffusion
• Cardiovascular disease includes all diseases of the heart and circulatory system
• Cardiovascular disease includes coronary heart disease, heart attacks, angina and strokes
• Atherosclerosis is when arteries become clogged with fatty substances(plaques) or atheroma
• atheroma can lead to heart attack when fatty deposits build up in the coronary arteries and become clogged
• Statins are a group of drugs that control blood cholesterol and reduce the chance of atherosclerosis
• angioplasty removes atheroma from arteries by medical procedure of inflating a balloon
• the system of blood travelling through to the lungs and back is called a pulmonary circulation
• the way of blood travelling to the body and back is called a systemic circulation