heart

• blood is made up of plasma, red blood cells, white blood cells and platelets.
• plasma is a liquid that transports water soluble substances such as urea, hormones, digested food and carbon dioxide.
• red blood cells transport oxygen and contain a red pigment called haemoglobin to attach oxygen.
• white blood cells fight diseases as a part of the immunity system.
• platelets are cell fragments that help clot blood.
• red blood cells are biconcave discs shape, they contain haemoglobin to absorb oxygen and have no nucleus so that they can carry more haemoglobin in the cytoplasm.
• white blood cells squeeze into tiny gaps of capillaries, phagocytes ingest bacteria and lymphocytes produce antibodies.
• blood is pumped around the heart and moves through blood vessels.
• the left halve receives oxygenated blood from the lungs and sends the blood to the body.
• the right halve receives de-oxygenated blood from the body and pumps it to the lungs.
• pulmonary circulation takes blood to and from the lungs.
• systemic circulation takes blood to and from the body.
• de-oxygenated blood enters through the vena cava then moves into the right atrium, tricuspid valve, right ventricle, and out the pulmonary artery into the lungs. oxygenated blood returns to the left side through the pulmonary vein and into the left atrium, bicuspid valve, left ventricle, and out the aorta. The aorta pumps the blood around the body.
• the left side is muscular and thick as it is under high blood pressure in order to pump blood for the body.
• lungs receive oxygen and diffuse out carbon dioxde.
• the heart pumps blood around the body.
• the heart has branches of coronary arteries and branches of coronary veins.
• capillaries penetrate all tissues, they are very small and narrow, they have one cell thick walls to allow diffusion of oxygen and nutrients in and carbon dioxide out, they form huge networks that link arteries and veins, blood is under low pressure.
• veins carry blood towards the heart, they are under low blood pressure, they carry deoxygenated blood (except for the pulmonary vein), they have thin flexible walls (thick tough outer layer, muscular middle layer, thin inner layer of cells.), they have a large lumen, no pulse and valves are present.
• arteries carry blood away from the organs, they are under high blood pressure, they carry oxygenated blood except for the pulmonary artery, they have thick elastic walls (thin tough outer layer, thick muscular middle layer, thin inner layer of cells.), they have a small lumen, there is a pulse and valves are absent.
• the heart is made of cardiac muscle.
• cardiovascular diseases include coronary heart disease, heart attacks, strokes and angina.
• coronary heart disease is the blockage of artery causing lack of oxygen into the heart muscle. there is a narrow rupture to the walls making them thin.
• atherosclerosis is the build up of plaque in the arteries, it makes it hard for the blood to flow and blocks in small arteries and can cause a heart attack, blockage in the coronary artery results in chest pain, when the blood flow is slow blood clots form which results in a stroke.
• bicuspid and tricuspid valves are between the atria and ventricles, valves prevent black flow, semi-lunar valves are at the beginning or the aorta and pulmonary artery to make sure blood doesn’t get sucked back in when heart relaxes.
• risking factores of cardiovascular disease consist of high blood pressure, smoking, high blood cholesterol, diabetes, obesity, lack of exercise, family history and ethnic background.
• lifestyle changes consist of giving up smoking, low fat and high fibre diet for less cholesterol and exercising.
• the advantages of lifestyle changes are that they prevent problems before they occur, relatively cheap and improves your wellbeing.
• the disadvantages of lifestyle changes are that results take time, willpower is needed and exercise needs to be built up gently.
• statins are drugs thar reduce bad low density lipoprotein (LDL) cholesterol.
• the advantages of statins are that they reduce LDL cholesterol, lowers the rate of strokes, heart disease and attacks, they increase HDL cholesterol and prevent other diseases such as dementia.
• the disadvantages of statins are that there are side-effects (headaches, kidney, failure, liver, damage, memory loss.), results take time, and they must be taken long term.
• angioplasty keeps the arteries open by pushing a balloon in the artery to flatten the fatty deposits.
• the advantages of angioplasty are that it lowers the risk of coronary heart disease, short procedure & recovery time and they work for a long time.
• the disadvantages of angioplasty are that there may be surgery complications such as infection or even a heart attack, thrombosis (blood clot near the stent) which can be life threatening, some patients need blood thinning medication for the rest of their lives.