Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Topic 13 – The Use and Abuse of Drugs `````````` 13.1 – Antibiotics, 13.2 – Effects of heroin, 13.3 Effects of alcohol, 13.4 – Effects of tobacco smoke SUFEATIN SURHAN BIOLOGY MSPSBS 2010 SYLLABUS CHECKLIST Candidates should be able to: a) Define a drug as any externally administered substance that modifies or affects chemical reactions in the body; b) describe the medicinal use of antibiotics for the treatment of bacterial infection; c) describe the effects of the abuse of heroin: a powerful depressant, problems of addition, severe withdrawal symptoms and associated problems such as crime and infection e.g. AIDS; d) describe the effects of excessive consumption of alcohol: reduced self-control, depressant, effect on reaction times, damage to liver and social implications; e) describe the effects of tobacco smoke and its major toxic components (nicotine, tar and carbon monoxide) on health: strong association with bronchitis, emphysema, lung cancer and heart disease, and the association between smoking during pregnancy and reduced birth weight of the baby; f) recognize the fact that many people regard smoking as no longer socially acceptable. Hormones are chemicals naturally present in the body which USES OF DRUGS affects chemical reactions. However, external chemicals can Drugs may be used for beneficial effects: also be used to change or affect chemical reactions in the body. These are drugs. a) For treatment of diseases such as antibiotics. - Definition of a Drug pneumonia, syphilis and gonorrhoea, which are An externally administered chemical substance which modifies or affects chemical reactions in the body. This class of drugs only treats diseases such as specifically caused by bacteria. - When consumed, antibiotics only kill the diseasecausing bacteria but they do not affect the normal Drugs can be administered into the body by four ways: body cells at all. 1. By oral consumption. 2. By injection. 3. By inhalation. preventing the synthesis of bacterial cell wall, hence, 4. By application onto the skin. the bacteria die by lysis due to osmotic pressure. - One mechanism by which antibiotics kill bacteria is by - - - - - - A well known antibiotic is penicillin, which is made - from the blue-green mould / fungus, Penicillium. In (numbness), removes feelings of anxiety and creates the treatment of syphilis, this is given by injection. a sense of extreme well being (euphoria). Other common antibiotics are tetracycline and - Its use in medicine is highly controlled due to its amphiciline. highly addictive nature where it is used for the relief The full course of the antibiotics given must be of severe pain only. completed in order to ensure the death of all of the The body can become tolerant to heroin i.e. progressively disease-causing bacteria in the body. increased dosages of the drug is required to maintain the If the antibiotic course is not completed, some same feelings of well being. bacteria may survive and evolve a defensive - mechanism against the antibiotic, making them The abuser may end up in a state of dependence, where resistant to the antibiotic. they crave the drug and cannot face life without it. Future treatment against this resistant strain of - This poses the danger of death from over dosage. In the absence of the drug, they suffer from severe bacteria with this antibiotic will no longer be withdrawal symptoms such as diarrhea, vomiting, effective. A different and stronger antibiotic will need muscular pain, shaking and hallucination. to be used. Addiction often results in social problems as follows: The fact that antibiotics may be successful in helping 1. Obsession on obtaining the drug means that they are to cure a bacterial infection when the immune system unable to concentrate on their job, inevitably leading can no longer cope was not often mentioned, but to unemployment. that such conditions may be cured more quickly with - As a consequence, there is no money for them to the aid of antibiotics was well known. support their expensive habit as well as to Disadvantages: possible allergic reactions. support their family. - b) For pain relief i.e. as pain killers such as paracetamol, c) It results in a sedative effect i.e it dulls the senses They then tend to resort to a life of crime to aspirin, morphine, heroin. obtain money for regular access to the drug as For treating emotional disorders such as depression. well as having dysfunctional families (divorce). 2. The sharing of unsterilized needles between several DEFINITION OF DRUG ABUSE users means that they are at a high risk of contracting When a drug is taken simply for enjoyment/recreational blood-borne diseases such as hepatitis and HIV / AIDS. purposes, often in large amounts and often leads to addiction. ALCOHOL – A depressant drug Heroin, alcohol and nicotine are three drugs which are A widely used and readily available (legal) drug in many commonly abused and their effects on the body and the societies - Generally regarded as a ‘socially acceptable’ society are listed below drug. HEROIN – A depressant drug It is a depressant affecting the cerebrum and the cerebellum resulting in the following: Normally taken into a vein via a hypodermic needle. It is a powerful depressant Result of effect on cerebrum: - 2 |S u f e a t i n S u r h a n / B i o l o g y / M S P S B S 2 0 1 0 It creates a feeling of well being - Blurry vision also from physical violence or sexual abuse, which - Slurred speech often accompanies alcoholism. - Poor concentration and judgement - When consumed in increasing quantities, it leads to which many innocent people have been killed in road reduced and eventually loss of self control (loss of accidents. inhibition) causing the person to behave in a way - Drunk drivers are the cause of many fatal accidents in NICOTINE – A stimulant drug they would be ashamed of when sober. Effects of smoking on health Result of effect on cerebellum: Cigarette smoke contains around 4000 harmful chemicals. - It slows down reaction times due to the resultant Some of them are nicotine, tar, carbon monoxide and poor muscle coordination. This, as well as the above irritants. effects, increases the risk of accident when a drunk Their effects on health are summarised below: person drives. Component Nicotine Question: How does alcohol enter the bloodstream? What is the actual effect of alcohol on neurons? In the long term, it also leads to liver damage such as liver Tar cirrhosis and cancer which can eventually prove fatal. - Why is liver affected? It also results in malnutrition since alcoholics tend to only consume the non-nutritional alcoholic drinks in excess (no balanced diet), often leading to obesity (‘Beer belly’) as the excess alcohol molecules (high calorie value) are Carbon monoxide converted into fats and stored in the adipose tissues in the body. It is also highly addictive (become an alcoholic) - Its withdrawal symptoms are less severe than that of heroin but a person may go to great lengths to satisfy their cravings. - Often families suffer as a consequence (family breakdown), not only from financial hardship, but 3 |S u f e a t i n S u r h a n / B i o l o g y / M S P S B S 2 0 1 0 Irritants Effect/s A highly addictive drug. - May cause relatively mild withdrawal symptoms if craving for nicotine not satisfied. A stimulant: stimulate adrenaline production, which increases heart rate and blood pressure. Causes constriction of blood vessels. Increase blood clotting, hence, increased risk of thrombosis (blockage in a blood vessel due to blood clot). A dark brown sticky substance, which enters the lungs as minute aerosol droplets. Stains teeth and fingers of smokers. Forms a layer over the epithelial cells of the walls of the alveoli, restricting gaseous exchange. A carcinogen (cancer causing substance) o Prolonged exposure to it may lead to lung cancer which may metastasize to other parts of the body A colourless and odourless poisonous gas. Combines with haemoglobin in red blood cells permanently / irreversibly forming carboxyhaemoglobin (instead of with oxygen). - Greatly reduce the ability of the blood to carry oxygen. Damages lining of blood vessels and increases formation of atheroma of their walls. Cause cells lining the bronchi and bronchioles to increase their production of mucus, narrowing the air passages. Results in ‘smoker’s cough’ which provides a temporary relief since coughing temporarily displaces the thick mucus. However, prolonged coughing may damage the walls of the alveoli causing them to become overstretched and may lead to emphysema. Destroy the cilia lining the trachea, increasing the chances of inflammation of the bronchial walls and may lead to bronchitis. This is further worsen by nicotine, which constricts the maternal arteries in the placenta. Hence, less oxygenated blood and nutrients can reach the foetus. Babies born to mothers who smoke during pregnancy have been shown to be: - Bronchitis nutrients and oxygen). Bronchitis is an inflammation of the bronchial tubes, - particularly the bronchioles. This results in the production of large quantities of thick mucus or phlegm which the person coughs up frequently. Emphysema foetal stage). - Having a greater risk of miscarriage, premature births and stillbirths. Passive smoking Evidence now exists that breathing the smoke from other be difficult to breathe out air from the alveoli and the people’s cigarettes can be harmful (inhalation of bronchioles. The alveoli will then become stretched to an unfiltered second-hand smoke). abnormal degree. Cigarette smoke is certainly an irritant to the eyes and Coughing will weaken the walls of the alveoli, causing leaves a lingering smell in clothes. them to break down, and holes appear. Smoking is therefore increasingly becoming a socially The surface area for gas exchange will be reduced and unacceptable habit. Heart diseases Large proportions of people who die from coronary heart disease are heavy smokers. It is associated with the deposition of fatty material in the lining of the coronary artery due to the increase in the blood clotting effect of nicotine.. This reduces the flow of blood to the heart muscles and the heart muscle is deprived of oxygen. Pregnancy and Smoking A pregnant woman who smokes also risks the health of her baby. Carbon monoxide causes less oxygen to reach the foetus as the carbon monoxide combine with the haemoglobin in the mother’s red blood cells to form a compound called carboxy-haemoglobin that cannot transport oxygen. (CO + Hb COHb) |S Less intelligent (brain development affected in the When phlegm accumulates in the bronchial tubes, it will breathing efficiency is affected. 4 Underweight (slow physical growth due to insufficient u f e a t i n S u r h a n / B i o l o g y / M S P S B S 2 0 1 0