B7 - Non-Communicable Diseases (Y10 - Summer 1) Flashcards
🟢 What Factors Affect/Risk Disease
There are many risk factors for disease, including the genes you inhert from your parents are your age, which you simply can’t change. Risk factors for disease also include:
- Aspects of your lifestyle such as smoking, lack of exercise, or overeating
- Substances that are present in the environement or in your body such as ionising radiation, UV light from the sun, or second-hand tobacco smoke.
Certain lifestyle factors, or environmental substances have been shown to increase your risk of developing particular disease. Risk factors for non-communicable diseases vary from differing diseases. Examples of risk factors can include diet, obesity, fitness levels, smoking, drinking alcohol, and exposure to carcinogens in the environment such as ionising radiation. We are able to influence, change, and remove many of these factors if we choose.
🟢 What Are Causal Mechanisms
It is useful to find correlations between lifestyle factors and particular diseases. Then, doctors and scientists need to do lots of research to discover if there is a causal mechanism. A causal mechanism explains how one factor influences another through a biological process. If a casual mechanism can be demostrated, there is a link betweenthe two. Dor example, there is a clear casual link between smoking tobacco and lung cancer. Anyone can get lung cancer, but smoking increase the risk becauze you take carcinogens into your lungs.
🟢 Impact Of Non-Communicable Diseases
Diseases cost nations and local communities huge sums of money both in the expense of treating ill people and in the loss of money earned when large numbers of the population are ill. The global economy suffers too, especially when diseases affect younger, working-age populations. Non-communicable diseases affect far more people than communicable diseases, so they have the greatest affect at both human and economic levels.
❌ What Are Tumours
Tumour cells do not respond to the normal mechanisms that control the cell-cycle. They divide rapidly with very little non-dividing time for growth in between each division. This results in a mass of abnormally growing cells called a tumour. Some tumours are caused by communicable diseases, like the human papilloma virus (HPV) can cause cervical cancer.
❌ What Are Benign Tumours
Benign tumours are growths of abnormal cells contained in one place, usually within a membrane. They do not invade other parts of the body, but a benign tumour can grow very large, very quickly. If it causes pressure or damage to an organ, this can be life-threatening. For example, benign tumours on the brain can be very dangerous because there is no extra space for them to grow into.
❌ What Are Malignant Tumour Cells
Malignant tumour cells can spread around the body, invading neighbouring healthy tissues. A malignant tunour is often referred to as cancer. The initial tumour may split up, releasing small clumps of cells into tne bloodstream or lymphatic system. They circulate and are carried to different parts if the body where they may lodge in another organ. Then they continue their uncontrolled divsion and form secondary tumours. Cancer cells not only divide more rapidly than normal cells, they also live longer. The growing tumour often completely disrupts normal tissues and, if left untreated, will often kill the person. Because of the way malignant tumours spread around the body, it can be very difficult to treat them.
❌ What Can Cause Cancer
Scientists still do not understand what triggers the formation of most cancers, but some of the causes are well known.
- There are clear genetic risk factors for some cancers including early breast and ovarian cancer
- Most cancers are the result if mutations - changes in the genetic material. Chemicals such as asbestos and the far found in tobacco smoke can cause mutations that trigger the formation fo tumours. These cancer-causing agents are called carcinogens
- Ionising radiation, such as UV light and X-rays, can also interrupt the normal cell cycle and cause tumours to form. For example, melanomas appear when there is uncontrolled growth of pigment-forming cells in the skin as a result of exposure to UV light from the Sun
- About 15% of human cancers are caused by virus infections. For example, cervical cancer is almost always the result of infection by HPV. Teenagers in the UK are now routinely vaccinated against the virus.
❌ How Can Cancer Be Treated
Because of the way cancer can spread through the body, it can be difficult to treat. In recent years, treatments have become increasingly successful. Scientists now are developing new treatements, and are also finding that combining some older treatments makes the more successful too.
The two mains ways cancer is treated at the moment is through:
- Radiotherapy, when the cancer cells are destroyed by targeted doses of radiation. This stops mitosis in the cancer cells but can also damage healthy cells. Methods of delivering different types of radiation in very targeted ways are improving cure rates
- Chemotherapy, where chemicals are used to either stop the cancer cells dividing or to make them ‘self-destruct’. There are many different types of chemotherapy and scientists are working to make them as specific to cancer cells as possible.
🟢 What Is Nicotine, And The Affect Of Carbon Monoxide
Nicotine is the addictive but relatively harmless drug found in tobacco smoke. It produces a sensation of calm, well-being, and ‘being able to cope’ and this is why people like smoking. Unfortunately some of the other chemicals in tobacco smoke can cause lasting and often fatal damage to the body cells.
Carbon monoxide is a poisonous gas found in tobacco smoke and it takes up some of the oxygen-carrying capacity of your blood. After smoking a cigarette, up to 10% of the blood will be carrying carbon monoxide rather than oxygen. This can lead to a shortage of oxygen, one reason why many smokers get more breathless when they exercise.
🟢 What Happens When You Smoke During Pregnancy
Oxygen shortage is a particular problem in pregnant women who smoke. During pregnancy, a woman is carrying oxygen for her developing fetus as well as herself. If the mother’s blood is carrying carbon monoxide, the fetus may not get enough oxygen to grow properly. This can lead to premature births, low birthweight babies and even stillbirths. There are around 3500 stillbirths in the UK each year, and scientists estimate around 20% of these are from mother smoking in their pregnancy.
🟢 Carcinogens Resulting From Smoking
The cilia in the trachea and bronchi that move mucus, bacteria, and dirt away from the lungs are anaesthetised by some of the chemicals in tobacco smoke. They stop working for a time, allowing dirt and pathogens down into the lungs and increasing the rosk of infections. Mucus also builds up over time and causes coughing.
🟢 What Is Tar And How’s It A Carcinogen
Other toxic compounds in tobacco smoke include tar. This is a sticky, black chemical tnat accumulates in the lungs, turning them from pink to grey. Along with other chemicals in the smoke, tar makes smokers much more likely to develop bronchitis (inflamation and infection if the bronchi). The build-up of tar in the delicate lung tissue can lead to a breakdown in the structure of the alveoli, causing chronic obstructive pulmonary disease (COPD). This reduces the surface area to volume ratio of the lungs, leading to severe breathlessness and eventually death.
Tar is also a carcinogen. It acts on the delicate cells of the lungs and greatly increases the risk of lung cancer developing. Tar also causes other cancers of the breathing system, for example, the troat, larynx, and trachea.
🟢 How Does Smoking Affect The Heart
The chemicals in tobacco smoke also affect the heart and blood vessels. Scientists have data showing that smokers are more likely to suffer from cardiovascular problems that non-smokers. They have also worked out the mechanisms that show it’s a causal link, not just a correlation.
Smoking narrows the blood vessels in your skin, ageing it. Nicotine makes the heart rate increase whilst other chemicals damage the lining of the arteries. This makes coronary heart disease more likely, and it increases the risk of clot formation. The mixture of chemicals in cigarette smoke also lead to an increase in blood pressure. This conbination of effects increases tne risk of suffering cardiovascular disease including heart attacks and strokes.
🟢 How Do Diet, Exercise, And Obesity Affect Each Other
If you eat more food than you need, the excess is stored as fat. You jeed some body fat to cushion your internat organs act as energy store. However, over time regularly eating too much food eill make you overweight and then obese.
Carrying too much weight can be uncomfortable, but obesity can actually lead to serious health problems, such as type 2 diabetes, high blood pressure, and heart disease.
🟢 How Do Exercise And Health Affect Disease
The food your eat transfers energy to your muscles as they work from repiration, so the amount of exercise you do affects the amount of respiration in your muscles, and the amount of food you need. People who exercise regularly are usually much fitter than people who take little exercise and have fitter hearts and bigger lungs as a result. Also, more exercise leads to making bigger muscles, which can be up to 40% of their body mass. However, exercise doesn’t always mean time working out and training, it can include walking to school and running around too. Also, it is now fact that people who exercise regularly are less likely to develop cardiovascular disease than people who don’t.
🟢 How Does Food Intake Affect Health And Disease
Between 60% and 75% of your daily food intake is needed for the basic reactions that keep you alive. About 10% is needed to digest your good so only the final 15%-30% is affected by your physical activity.
🟢 What Causal Mechnaisms That Explain Why Exercise Keeps You Healthy
These are some causal mechanisms that explain why exercise keeps you healthy. You will have more muscle tissue, increasing your metabolic rate, so you are less limely to be overweight. This reduces the risk of developing arthiritis, diabetes, and high blood pressure, for example. Your heart will be fitter and develop a better blood supply. Regular exercise lowers your blood cholesterol levels and helps the balance of the different types of cholesterol. This reduces your risk of fatty deposits building up on your cornonay arteries, so lowering your risk of heart disease and other health problems.
🟢 What Causes Obesity And Type 2 Diabetes
In type 2 diabetes, either your body doesn’t make enough insulin tp control your blood sugar levels or your cells stop responding to insulin. This can to problems with circulation, kidney function, and eyesight, which may eventually lead to death. Type 2 diabetes gets more common witn age, and some people have a genetic tendancy to develop it. The evidence is now overwhelming that being overweight or obese and not doing much exercise are risk factors for type 2 diabetes at any age, while this disease is becoming increasing common in young people. Fortunately, most people can restore their normal blood glucose balance by eating a balanced diet with controlled amounts of carbohydrates, losing weight, and doing regular exercise.
🟢 What Is Alcohol And How Does It Affect Your Health
Alcohol is a commonly used social drug in many parts of the world. It is poisonous but the liver can usually remove it before permanent damage or death results. Alcohol is also very addictive.
After an alcoholic drink, the ethanol is absorbed into the blood from the gut and passes easily into the body tissues, including the brain. It affects the nervous system, making though processes, reflexes, and many reactions slower than normal. In small amounts, alcohol makes people feel relaxed, cheerful, and reduces inhibitions. Larger amounts lead to lack of self-control and judgement. If the dose of alcohol is too high, it can sometimes lead to unconciousness, coma, and death.
🟢 How Can The Brain And Liver Be Damaged By Alcohol
People can easily become addicted to alcohol, needing the drug to function, and they may drink heavily for hears. Their liver and brain may suffer long-term damage and eventually the alcohol can kill them:
- They may develop cirrhosis of the liver, a disease that destroys the liver tissue. The active liver cells are replaced with scar tossue that cannot carry out vital functions.
- Alcohol is a carcinogen, so heavy drinkers are at increased risk of developing liver cancer. This usually soreads rapidly and is difficult to treat.
- Long-term heavy alcohol use also causes damage to the brain. In some alcoholics, the brakn becomes so soft and pulpy that the normal brain structures are lodt and it can no longer finction properly. This can cause death.
The damage to the liver and brai associayed with heavy drinking usually develops over years, but hort bouts of very heavy drinking risk the same symptoms appearing relatively fast, even in young people.
🟢 How Can Alcohol Affect A Pregnant Woman’s Baby
If a pregamt woman drinks alcohol, it passes across the placenta into the developing baby. Miscarriage, stillbirths, premature births, and low birthweight are all risks linked to drinking alcohol during pregnancy. The developing liver will noy be able to cope with the alcohol, so the brain and body will be badly affected, especially in the early stages.
The baby may have facial deformities, probelms with it’s teeth, jaw or hearing, kidney, liver, and heart problems, and may have learning and other developmental problems. This is known as fetal alcohol syndrome (FAS). Doctors are not sure how mucn alcohol is safe during pregnancy, so the advice given, is to not drink it at all, as the more alcohol, the higher the risks.
🟢 What Is Ionising Radiation And How Does It Work
Ionising radiation in the form of different types of electromagnetic waves is a well-known carcinogen (risk factor for cancer). Radioactive materials ate a source of ionising radiation. The radiation penetrates the cells and damages the chromosomes, causinh mutations in the DNA. The more you are exposed to ionising radiation, the more likely it is that mutations will occur and that a cancer will develop.
🟢 How Is Ionising Radiation Dangerous And The Sources Of It
Ionising radiation is particularly dangerous when taken directly into your body. For example, breathing radioactive materials into the lungs enables the ionising radiation to penetrate directly into the cells. Well-known sources of ionising radiation include:
- Ultraviolet light from the sun - this increases the risk of skin cancers such as melanoma (protection includes sunscreen and sensible clothing)
- Radioactive materials found in the soil, water, and air (including radon gas in granite-rich areas such as Cornwall and the Pennines)
- Medical and dental X-rays
- Accidents in nuclear power generation, especially accidents such as the one in Chernobul, Ukraine in 1986 can spread ionising radiation over wide areas.
