Drugs and how they work


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Drugs and how they work

  1. 1. Drugs and how they work
  2. 2. What are drugs A drug is any substance that is taken into the body that alters or influences chemical reactions in the body.
  3. 3. Types of drugs Medical drugs These drugs are designed to suppress pain , counteract the symptoms of flue or kill pathogenic bacteria Aspirin Paracetamol Morphine Antibiotics
  4. 4. Types of drugs Hallucinogens These drugs cause psychedelic visions for the drug user. Lysergic Acid Diethylamide or LCD
  5. 5. Types of drugs Stimulants These are mood-enhancing drugs which give the user a short-lived feeling of wellbeing and energy. Examples Cocaine , ecstasy and amphetamines.
  6. 6. Types of drugs Depressants (downers) Slow down the brain and central nervous system. Examples are alcohol, beer, wine, vodka, gin etc heroin, tranquilizers, sleeping pills
  7. 7. Drugs in the body Drugs such as nicotine and heroin , interfere with the way that the nervous system works. Mood-enhancing drugs, such as heroin and nicotine act at synapses in the nervous system and change the way in which neurons send impulses. Drugs are broken down in the body by enzymes and the products are excreted.
  8. 8. Drug addiction Many drugs have the potential to be addictive. If the body comes to rely on the drug a person can become addicted and feel the need to take it regularly. The body’s metabolism may become used to the drug. The liver may produce more enzymes to break it down so that the dose of the drug has to increase to have the same effect the user first experienced.
  9. 9. Drug tolerance in the case of heroin, synapses may produce more target molecules and if these do not combine with heroine this leads to an increase in the feeling of pain. The person has become dependent on the drug and cannot survive without it. When the people stop taking the drug they may experience withdrawal symptoms which can vary from nausea to severe cramp.
  10. 10. Antibiotics Antibiotics are a group of chemicals made by microorganisms (bacteria and fungi) that are used in chemotherapy as they kill pathogens or stop their growth. Antibiotics destroy pathogens by disrupting cell wall formation, inhibiting protein synthesis and metabolism in the pathogen cell.
  11. 11. Antibiotics Antibiotics cannot kill viruses since they have no cell wall and live inside host cell, taking over their metabolic processes.
  12. 12. HEROIN Biology of heroin Heroine is a compound modified from morphine. Heroine is a powerful depressant that slows down the nervous system. Heroine resembles the natural body’s painkillers, known as a natural opiate. First time users experience euphoria- feeling of contentment and intense happiness.
  13. 13. Addiction to heroin Heroin becomes part of the body’s metabolism and the body quickly gets used to the drug. More painkillers are needed to prevent them sending impulses to the brain. But the body does not produce more of its own natural painkillers.
  14. 14. Social problems Heroin addicts may turn to crime to obtain money for their next dose. Shared needles have resulted in the spread hepatitis and HIV amongst addicts who inject heroin. A user who stops taking the drug experiences very un pleasant withdrawal symptoms. These can include sleeplessness and hallucinations, muscle cramps, sweating, vomiting and nausea.
  15. 15. Alcohol Biology of alcohol Alcohol is absorbed into the blood very quickly since it is small molecule that does not need to be digested It is absorbed by liver cells and broken down by enzymes so that its concentration in the blood decreases gradually. Alcohol is a depressant. It affects the brain by slowing down the transition of nerve impulses.
  16. 16. Social problems of alcohol Crime , family disputes, marital breakdown, child neglect and abuse, absenteeism from work, vandalism, violent crime including murder. Alcohol and other drugs are involved in many road accidents.
  17. 17. Long-term effects of alcohol Stomach ulcers, heart disease and brain damage. If heavy drinking continues then the liver becomes full of nodules. This is the condition known as cirrhosis.
  18. 18. Smoking and health components of tobacco smoke Biology of tobacco smoke Nicotine It is absorbed very quickly through the alveoli to enter the bloodstream. Nicotine makes the heart beat faster and narrows the arterioles. - Tar Is a black sticky material that collects in the lungs as a smoke cools. Tar irritates the lining of the airways and stimulates them to produce more mucus.
  19. 19. Components of tobacco smoke Carbon monoxide This is a poisonous gas. It is absorbed by hemoglobin in red blood cell. It reduces the volume of oxygen that blood can carry.
  20. 20. Diseases caused by smoking Chronic bronchitis and emphysema The bronchi become blocked as there is less space for air to flow. Large amounts of mixture of mucus, bacteria and white blood cells are produced, which people attempt to cough up. The break down of alveoli becouse of partcles bacteria and tar , reducing gas exchange is called emphysema.
  21. 21. Diseases caused by smoking Lung cancer Heart desease
  22. 22. Questions ??