REDUCING RISK A person’s risk of developing coronary heart disease can be reduced by: DIET should be energy balanced reduced cholesterol, saturated fats and salt more polyunsaturated fats, including omega-3 fatty acids found in oily fish more fruit and vegetables...
LIPIDS Lipids contain the elements carbon, hydrogen and oxygen. They are insoluble in water but soluble in organic solvents (ethanol). They provide twice as much energy as carbohydrates and supply the body with essential fatty acids. Vitamins are often found dissolved...
CHOLESTROL Insoluble cholesterol combines with proteins to form soluble lipoproteins so that it can be carried in the bloodstream. Eating both monounsaturated and polyunsaturated fats reduces the level of LDLs in the blood.
TISSUE FLUID How is Tissue Fluid formed? At the start of the capillary bed, the arteriole end, there’s high pressure due to the contraction of the ventricle This pressure is called hydrostatic pressure and it forces fluid out of the capillaries into the spaces...
ENERGY BUDGET + DIET Carbohydrates, proteins, lipids and alcohol all contain energy: used to be measured in calories; the SI unit is the Joule. Average person requires 8,000-10,000 kilojoules per day. Dietary Reference Values encourage balanced & healthy diets and...
STUDIES Epidemiologist – studies patterns in the occurrence of diseases Cohort studies – follows a group of people over time to see who develops the risk and who doesn’t Case-control studies – people with the disease are compared to people without Controls should be...
BLOOD PRESSURE Blood pressure is higher in arteries and capillaries than in veins. Systolic blood pressure is highest and occurs when the ventricles contract (ventricular systole) Diastolic blood pressure is at its lowest in the arteries when the ventricles...
BLOOD CLOTS Platelets are cells with no nucleus. But when platelets come in contact with the damaged vessel their shape changes into a “spiky” shape – they stick to each other and the collagen in the wall: a platelet plug is formed. They then release more substances...
RISK Probabilities E.g. 24,000 people died in 2005. The population was 72,200,000. What is the average risk in: Percentage: 24,000 / 72,200,000 = 0.033% Fraction: 72,200,000 / 24,000 = 1 in 3008 people These averages make the assumption that everyone has the same...
RISK FACTORS FOR CVD The following factors increase a person’s risk of developing cardiovascular disease: GENETIC Risk is increased if your parents have CVD. Different chances of inheriting the defective genes; two recessive / one dominant allele = inherited...
ATHEROSCLEROSIS
BLOOD VESSELS When muscles relax, the lumen widens thus decreasing B.P There is no pulse and pressure is low. Valves prevent backflow.
PROPERTIES OF WATER Thermal Properties Large amounts of energy are needed to break the hydrogen bonds. Because organisms have a high water content, a large amount of energy only results in a small increase in body temp. This means that water warms and cools slowly....
TRANSPORT IN ANIMALS Circulatory Systems OPEN CIRCULATORY SYSTEM- In invertebrates (e.g. insects), blood isn’t held within vessels always It’s free to circulate the body cavities (spaces) Only works for insects because they’re small Cannot contain any pressure,...