1.3 Risk factors for cardiovascular disease Flashcards
Cohort study
Follow a large group of people over time to see who develops the disease and who doesn’t.
Prospective study
Framingham heart study
Case control study
a group of people with a disease are compared with a control group who do not have the disease. Info is collected about the risk factors they may have been exposed to.
Retrospective study
Richard Doll and Austin Bradford Hill lung cancer study
Features of a good study
- Clear Aim
- Representative sample
- Valid and reliable results
- Sample size
- Controlling variables
Risk factors for CVD
- High blood pressure
- Obesity
- Blood cholesterol and other dietary factors
- smoking
- inactivity
- genetic inheritance
Hypertension
High blood pressure, which occurs even when a person is at rest. It is thought to be one of the most important factors in the development of cardiovascular disease.
Blood pressure
Measure of the hydrostatic force of the blood against the walls of a blood vessel.
measured in mmHg
systolic between 100 and 140 mmHg
Diastolic between
60 and 90 mmHg
Systolic pressure
The blood pressure during the phase of the cardiac cycle when the ventricles are relaxed.
Diastolic pressure
The blood pressure during the phase of the cardiac cycle when the ventricles are contracting.
Sphygmomanometer
A traditional device used to measure blood pressure. It consists of an inflatable cuff that is wrapped around the upper arm, and a manometer or gauge that measures pressure.
Peripheral resistance
contact between blood and the walls of the blood vessels causes friction and this impedes the flow of blood
High blood pressure caused by …
natural loss of elasticity with age, high salt diet, release of hormones such as adrenaline
Oedema
Swelling caused by the accumulation of tissue fluid. For instance, tissue fluid is formed at the arteriole end of a capillary. It filters back into the venule end of the capillary. Excess tissue fluid is normally returned to the blood system via the lymphatic system. Oedema results when more tissue fluid is formed than is returned either through the venule end of the capillary or through the lymphatic system. There are various causes of oedema, including high blood pressure, starvation and blocked lymph vessels.
Tissue fluid, Interstitial fluid
The fluid that surrounds the cells in the body, supplying them with the substances they need, and taking away waste products. Tissue fluid is formed when plasma is forced out of capillaries. It contains water and all the small molecules which make up blood plasma. The capillary walls, however, prevent blood cells and larger protein molecules from passing through. Tissue fluid is also called interstitial fluid.
Lymph vessels
The tubes that carry lymph – a colourless fluid, derived from tissue fluid, that is rich in lipids and contains many white blood cells.
Lymphatic system
A system of vessels which returns excess fluid to the blood system. Over the course of a day, more fluid leaves the capillaries of the blood system than returns to them. In a healthy person, this fluid drains into lymphatic capillaries and then into larger lymph vessels before returning to the blood in the veins in the neck.
Calorie Unit of energy.
One calorie is the amount of energy required to raise the temperature of 1 g of water by 1 °C. One calorie equals approximately 4.18 joules. Kilocalories, 1000 calories, are sometimes called Calories with a capital letter.
Kilojoule
Unit of energy equal to 1000 joules. The joule is the SI unit of energy. The amount of energy required to raise the temperature of 1 kg of water by 1 °C is about 4.2 kilojoules.
Kilocalorie
Unit of energy equal to 1000 calories. 1 kilocalorie is the amount of energy required to raise the temperature of 1 kg of water by 1 °C. The kilocalorie is often written as the Calorie (note the capital C to distinguish it from the calorie!) and is the unit of energy commonly used on foods and in diet books.
Carbohydrate
A substance containing the chemical elements carbon, hydrogen and oxygen. Carbohydrates get their name because the hydrogen and oxygen are always in the same proportion as they are in water – there are two atoms of hydrogen for every atom of oxygen.
Carbohydrates whose molecules are made up of
a single unit are called monosaccharides. These
units can be joined by condensation to produce
disaccharides like sucrose, and
polysaccharides such as starch and cellulose.
general formula Cx(H2O)n
Lipid
A group of substances found in all cells. Lipids do not dissolve in water but they are soluble in organic solvents such as ethanol. A number of different substances are classified as lipids. They include triglycerides, phospholipids and steroids.
Monosaccharide
A carbohydrate that is made up of a single sugar unit. Monosccharides are small molecules which dissolve readily in water. They are classified according to how many carbon atoms they contain. Hexoses such as glucose contain six carbon atoms. Pentoses such as ribose contain five carbon atoms. Monosaccharides join together to form disaccharides and polysaccharides.
general formula (CH2O)n
Disaccharide
A carbohydrate that is made up of two sugar units or monosaccharides. Maltose is a disaccharide. It is made of two molecules of glucose joined by condensation. Other biologically important disaccharides are sucrose and lactose.
Polysaccharide
A carbohydrate made up from a large number of sugar units or monosaccharides joined to each other by condensation. Starch is a polysaccharide. It is made up from glucose monomers and is an important storage substance. Cellulose is a structural polysaccharide found in plant cell walls. It is also built up from glucose monomers.
Condensation
A type of chemical reaction in which small molecules are joined together with the removal of a molecule of water. Condensation is involved in forming biologically important polymers. The reactions in which amino acids join to form proteins, and glucose molecules join to form starch and cellulose are examples of condensation reactions.
Hydrolysis, Hydrolyse
A chemical reaction where larger molecules are broken down into smaller ones by a reaction with water. Hydrolysis is very important in digesting biologically important polymers. The reactions where proteins break down to form amino acids, and starch molecules break down to form maltose and glucose are examples of hydrolysis.
Glucose
A simple sugar, which has six carbon atoms in each molecule. Glucose is very important in cellular respiration where it is broken down to release energy. Carbohydrates such as starch and cellulose are made from long chains of glucose molecules joined by condensation. The atoms in a glucose molecule can be arranged in different ways and this results in different forms of glucose. Two of these forms are alpha-glucose and beta-glucose.
