B7 Non Communicable diseases Flashcards
What is a non communicable disease?
It is a disease that cannot be passed from one individual to another
What are risk factors for non communicable diseases?
- genes inherited by parents
- age
- life style (smoking, lack of exercise, bad diet)
- substances present in your body or in the environment such as UV light from the sun, second hand tobacco smoke, radiations
What are causal mechanisms for non communicable diseases?
A causal mechanism explains how one factor influences another through a biological process. For example a causal link has been demonstrated between smoking tobacco and lung cancer. For other risk factors scientists only talk of correlation (similarities in patterns a link is only suggested)
Impact of non communicable diseases
- Financial for the whole society in terms of money spent for treating patients (taxes)
- Finacial if large parts of the population are sick
- Individual level
When do tumors form?
When cells grow in an abnormal, uncontrolled way. This results in a mass of abnormally growing cells called a tumor
What are benign tumors?
They are a growth of abnormal cells contained in one place, usually within a membrane. They do not invade other parts of the body. However, they can grow very large very quickly and if they put pressure on organs they can be life threatening.
What are malignant tumor cells?
These are cancers. They invade neighbouring tissues and might spread in different parts of the body. The initial tumor may split up and release small clumps of cells in the bloodstream or lymphatic system. They circulate and are carried to different parts of the body. Then they carry on their uncontrolled division and form a secondary tumor. These cells not only divide faster but also live longer than normal cells.
What causes cancer?
Some of the causes of cancer are well known:
- genetic risk factors for ovarian and breast cancer
- most cancers are results of mutations - changes in genetic material. Chemicals such as tar in tobacco smoke can cause mutations which then cause cancer
- Ionisin radiations uch as UV light and X rays can interrupt the normal cell cycle and cause tumors. eg melanoma in the skin
- 15% of human cancers are caused by viral infections. eg cervical cancer is almost always the result of infection by HPV (vaccination now for teens in UKagainst HPV)
How can cancer be treated?
- Radiotherapy: cancer cells are destroyed by targeted doses of radiations. This stops mitosis in cancer cells but can also damage healthy cells. Delivering this with very targeted ways might improve side effects
- Chemotherapy: where chemicals are used either to stop cancer cells from reproducing or make them self distruct
What is nicotine?
It is an addictive but relatively harmless drug found in tobacco
What is the poisonous gas found in tobacco smoke?
Carbon monoxide. It is dangerous because it takes up some of the oxygen carrying capacity of the blood. After smoking a cigarette 10% of the blood will be carrying carbon monoxide rather than blood. This causes smokers to be breathless
What are the risks of smoking in pregnancy?
If the mother smokes she is carrying carbon monoxide so the foetus might not get enough oxygen to develop properly. This can lead to premature birth, low birthweight, even still birth.
What is one of the toxic compounds found in smoke?
Tar. This is a sticky, black chemical that accumulates in the lungs turning them from pink to grey. It make sit more likely to develop inflammation and infections in the bronchi. Also the build up of tar can cause the breakdown of the aveoli, causing chronic obstructive pulmonary diseases. This reduces the surface area of the lungs leading to severe breathlessness and eventually death.
Tar is also carcinogen and greatly increases the risk of lung cancer developing. Also cancer of throat, larynx and trachea.
What is the effect of smoke on the heart and blood vessels?
Scientists have found a causal link between smoking and cardiovascular problems.
Smoking narrows the blood vessels ageing them. Nicotine makes the heart rate increase and other chemicals damage the lining of the arteries. This makes CHD more likely as well as clots. Also the mixture of chemicals increased=s blood pressure. Increased risk of heart attack and stroke
Why do exercise help to keep you healthy?
- You will have more muscles increasing your metabolic rate so you are less likely to be overweight. This in turn reduce the risk of developing arthritis, diabetes and high blood pressure for example.
- Your heart will be fitter and develop a better blood supply
- Regular exercise lowers cholesterol levels and helps the balance of different types of cholesterol. This reduces the risk of fatty deposits building up in your arteries.
