Biology Core- Drugs

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Introduction

A drug is a chemical that has an effect on the body.

Everybody thinks that drugs are just the illegal sort. But they also include useful medicines and also legal drugs.

Illegal Drugs

The drugs that society decides are

dangerous or addictive are made illegal. Using these drugs is a crime.

These are the 'street' drugs (cannabis, cocaine and heroin for example).

Different societies at various times have different views on which drugs should be illegal.

 

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Legal Drugs

The most obvious are the medicinal drugs, such as Penicillin, that are designed to deal with medical conditions. These are always rigorously tested, checked and their use reviewed.

However other substances in common usage are drugs too: Caffeine is a widely used drug, but its overuse can cause tissue damage.

Likewise tobacco and alcohol are legal drugs in most countries. Yet they too can have serious health effects.Drugs that affect our nervous systems and our mood can become addictive or habit-forming.However the word 'addictive' is often seen as just relating to illegal drugs. Therefore the word dependence is seen as a better alternative.

Drug dependence has two features:

  1. Chemical dependence
  2. Psychological dependence
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Chemical Dependence

This is where the body itself adapts to the presence of the drug. When the chemical is removed the body is no longer able to function normally.

The body then goes into withdrawal symptoms such as hallucinations, fevers, nausea (feeling sick) and shakes. These are real, physical signs.

Another term for chemical dependence is physiological dependence. Physiology is how the body functions normally.

Phychological Dependence

feels a need for the drug. They may also feel unable to cope without the drug.For example:

some smokers need to chew sweets after they give up because they miss having a cigarette in their mouths.

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Drugs and Their Effects

For the exam you need to be familiar with the following types of drugs and the effects they can have on the body.

Stimulants

A stimulant is a drug that increases the activity of the nervous system. It can raise the alertness, emotions or mood.

Caffeine is a mild stimulant found in tea and coffee. It is pretty harmless and most peoples' lives are not affected by it. Prolonged overuse may lead to problems with the heart, stomach and pancreas.

Amphetamine and methedrine are stronger stimulants. They induce a feeling of boundless energy but there is a deep depression after their use.People think that they are performing better than they actually are.The person rapidly becomes dependent and needs the drugs to maintain the highs. Continued usage can lead to personality changes and serious depression.

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Depressants

Depressants reduce the activity of the nervous system. They slow down your responses and make you sleepy.

Alcohol and barbiturates can cause slowed reaction times and poor judgement of speed and distance. They can lead to increased risk of accidents.

Barbiturates are used as tranquillisers. Overdosing can stop you breathing. Not a good idea.

 

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Hallucinagens

A hallucination is a weird interpretation of the world around you. LSD and Ecstasy can cause these, usually only with higher doses of Ecstasy.

At lower doses Ecstasy gives a feeling of boundless energy and universal love, but this mood - changing effect can lead to a growing dependence.

The feeling of energy leads to a danger of overheating, dehydration and collapse.

Solvents

These include a variety of chemicals found in everyday things like paint, glue and gas canisters. They affect your nervous system and heart. Solvents can cause hallucinations and can have very serious effects on body and personality. They cause damage to the kidneys, lungs, brain and liver.There is also a high risk of sudden death.

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Painkillers

These are useful medical drugs used by doctors to control patients' pain.They stop the impulses from pain receptors and neurones reaching the brain.

However they are often misused and lead to strong dependence and physical deterioration. Also their cost on the street leads many into committing crime to be able to afford to buy them.

Heroin and morphine are powerful painkillers. They provide a feeling of sleepiness and calm when first taken. Over time the person loses all motivation. They fail to look after themselves and rapidly deteriorate physically and mentally.

Falling into crime is a major problem, including prostitution and theft.

Aspirin is also a painkiller, a very mild one. However, people do overdose on it, usually accidentally. It has harmful effects, including stomach bleeding. Yeugh!

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Alcohol

In many cultures alcohol has awelcome and socially acceptable place. In limited use it helps to relax us. However if misused it has serious problems.

Contrary to popular belief, alcohol is a depressant. Initially it depresses your inhibitions, but then it depresses your consciousness and finally your essential functions. In other words, it can kill you!

The depressant effect leads to a loss of judgement that can lead to accidents and taking life-threatening risks.

It has a poisonous effect on the brain, liver and other organs. Long-term abuse can lead to cancer, memory loss and so on. It doesn't help your sex life either!

Alcohol dependence can see a downward spiral into loss of income, job, friends, family and life.

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Tobacco

Tobacco

Once it was seen as the sophisticated and cool thing to use. Some still see smoking as cool and grown up.

However is now known to have very serious health risks. It kills 20,000 people a year in the UK alone. And you pay for the privilege!

If you spend £20 a week on tobacco it is costing you £1,040 a year. If you then smoke from the age of 16 until 65, you would have spent £51,000 on the habit. That's forgetting about inflation!

What about the health effects? The nicotine in tobacco affects the nervous system and is strongly addictive but does not really effect your mood. There's no 'high'.

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There are also hundreds of cancer-causing chemicals in burning tobacco. These have been proved to cause lung cancers, heart and circulation problems.

The tar from tobacco clogs up your lungs and stops them working properly. This causes diseases like emphysema and bronchitis where the person has trouble getting enough breath.

The tar also stops the cilia that clear the lungs of mucus and bacteria from working. So you develop a lovely 'smokers cough' with all that yucky stuffin it. Hmmm... nice.

Some say that smoking helps keep them slim - but who wants to be slim, broke and smelly?

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Comments

Swallowtail

A concise set of summary cards on drugs and alcohol. It would be useful to summarise the information in a mind map or set of flash cards to further help memories  the information.

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