GCSE-ready- Home
- Lessons
- KS3 Science
- Drugs and health
Drugs and health
🎬 The doodle video for this lesson is coming soon. Subscribe on YouTube to see it first.
A drug is any substance that changes the way your body works. Some help us; others can do serious harm.
Medicinal and recreational drugs
Medicinal drugs, such as painkillers and antibiotics, are used to treat illness.
Recreational drugs are taken for the effect they have on the mind. Some are legal for adults, such as alcohol, nicotine (in tobacco) and caffeine. Others are illegal because they are so harmful.
Even medicines can harm you if they are misused.
Recreational drugs are taken for the effect they have on the mind. Some are legal for adults, such as alcohol, nicotine (in tobacco) and caffeine. Others are illegal because they are so harmful.
Even medicines can harm you if they are misused.
Effects on behaviour
Stimulants speed up the nervous system and make you feel more alert. Caffeine and nicotine are stimulants.
Depressants slow the nervous system down. Alcohol is a depressant: it slows reaction times and affects judgement, which is why drinking and driving is so dangerous.
Many drugs are addictive: the body becomes used to them, and stopping causes unpleasant withdrawal symptoms.
Depressants slow the nervous system down. Alcohol is a depressant: it slows reaction times and affects judgement, which is why drinking and driving is so dangerous.
Many drugs are addictive: the body becomes used to them, and stopping causes unpleasant withdrawal symptoms.
Effects on health
Alcohol: over many years can damage the liver and the brain.
Tobacco smoke: contains nicotine (addictive), tar (causes cancer) and carbon monoxide (reduces oxygen carried by the blood). Smoking causes lung cancer and heart disease.
Solvents (such as glue or aerosols) can damage the brain, liver and kidneys and can kill.
Tobacco smoke: contains nicotine (addictive), tar (causes cancer) and carbon monoxide (reduces oxygen carried by the blood). Smoking causes lung cancer and heart disease.
Solvents (such as glue or aerosols) can damage the brain, liver and kidneys and can kill.
A driver has drunk alcohol. Explain why they are more likely to crash.
- Alcohol is a depressant.
- It slows down the nervous system.
- So reaction times are longer and judgement is worse.
Answer: Alcohol slows the nervous system, so the driver reacts more slowly and judges distances badly.
A drug changes how the body works. Stimulants (caffeine, nicotine) speed up the nervous system; depressants (alcohol) slow it down. Many drugs are addictive. Alcohol damages the liver and brain; smoking causes lung cancer and heart disease.
Check you have got it
Answer 6 quick questions with instant marking. If you get one wrong, GCSE-ready shows you why and gives you another go. It is free, and you do not need an account.