2.8

• Adrenaline


  A hormone produced in the adrenal gland. It is released when the body is under acute stress or during exercise it increases blood flow to the skeletal muscles and the level of glucose in the blood.
• Atherosclerosis


  A disease in which fatty deposits called plaques build up on the lining of arteries. This causes the arteries to become clogged, restricting the flow of blood and the supply of oxygen round the body. Also known as hardening of the arteries.
• Blood pressure


  The force of blood against the artery walls.
• Carbohydrate


  Food belonging to this food group consist of sugars, starch and cellulose. Carbohydrates are vital for energy in humans and are stored as fat if eaten in excess. In plants, carbohydrates are important for photosynthesis.
• Cardiovascular disease (CVD)


  Disease relating to the heart and the blood vessels.
• Diabetes


  A serious disease in which the body is unable to regulate blood glucose level. It can be treated by injecting insulin.
• Diet


  The type and amount of food consumed by people.
• Endothelium


  A single layer of endothelial cells that line the interior surface of blood vessels and lymphatic vessels.
• Fasting


  Refraining from eating for a period of time.
• Glucagon


  A hormone produced by the pancreas that promotes the breakdown of glycogen into glucose in the liver
• Glucose


  A simple sugar used by cells for respiration.
• Glycogen


  Animals store glucose as glycogen in their liver and muscle tissues.
• Homeostasis


  The maintenance of steady conditions. The ability of the body to maintain a constant internal environment, eg. blood glucose concentration.
• Insulin


  A hormone produced by the pancreas that regulates the level of glucose concentration in the blood and can be produced by genetically modified bacteria.
• Lipid


  Fats or oils, composed of fatty acids and glycerol.
• Obesity


  The medical term for being very overweight, owing to the excessive accumulation of body fat in relation to lean body tissue such as muscle.
• Pancreas


  Large gland located in the abdomen near the stomach which produces digestive enzymes and the hormone insulin.
• Respiration


  The chemical change that takes place inside living cells, which uses glucose and oxygen to release the energy that organisms need to live. Carbon dioxide is a by-product of respiration.
• Negative feedback control of blood glucose

  1. Raised blood glucose level: Pancreatic receptors respond to raised blood glucose levels by increasing secretion of insulin from the pancreas. Insulin activates the conversion of glucose to glycogen in the liver decreasing blood glucose concentration.

  2. Lowered blood glucose level: Pancreatic receptors respond to lowered blood glucose levels by increasing secretion of glucagon from the pancreas. Glucagon activates the conversion of glycogen to glucose in the liver increasing blood glucose concentration.
• During exercise and fight or flight responses

  Glucose concentrations in the blood are raised by adrenaline, released from the adrenal glands, stimulating glucagon secretion and inhibiting insulin secretion
• Chronic elevated blood glucose levels can lead to the endothelium cells taking in more glucose than normal, damaging the blood vessels. This can cause atherosclerosis and blood vessel damage.
• Macrovascular disease


  Damage to large blood vessels
• Microvascular disease


  Damage to small blood vessels
• Type 1 diabetes


  Develops in childhood or early teens, pancreatic cells unable to produce insulin, cells have normal number of insulin receptors and respond to insulin, treated with regular insulin injections and careful diet
• Type 2 diabetes


  Develops in adulthood, pancreas able to produce insulin but cells have decreased number of insulin receptors making them less sensitive to insulin, treated with exercise, diet control and weight loss
• Testing for diabetes


  Urine tested for glucose as indicator, glucose tolerance test measures blood glucose changes after drinking glucose solution
• Obesity is a major risk factor for cardiovascular disease (CVD) and type 2 diabetes
• Body mass index (BMI)

  Body mass divided by height squared, BMI greater than 30 indicates obesity
• Obesity may be wrongly classified in muscular individuals using BMI
• Role of diet and exercise in reducing obesity and CVD

  • Obesity linked to high fat diets and decreased physical activity, exercise increases energy expenditure and preserves lean tissue, exercise can help reduce CVD risk factors