Drugs



Drugs are substances that change the way the body works. They can act on the nervous system by affecting the movement of nerve impulses along the fibres of nerve cells.

Most drugs are useful, but many are harmful and can easily kill if they are misused.

Useful drugs

Drugs such as aspirin and paracetamol are painkillers. They can be bought at the chemist for headaches and other pains. Tranquillizers and sedatives should only be obtained on prescription from a doctor. Tranquillizers calm people down. Sleeping pills are sedatives. The body can quickly become dependent on these drugs.


Anaesthetics are used to numb parts of the body. Dentists use local anaesthetics to numb your mouth. A general anaesthetic is used to put patients to sleep completely before an operation.


Harmful drugs

Unfortunately, some people use some drugs to give pleasant, short-term effects. It is easy to become addicted to harmful drugs and many drug addicts die. Many of these drugs affect behaviour and personality as well as having long-term effects on the brain.

The use or possession of controlled drugs such as cannabis, cocaine, and heroin is illegal in most parts of the world.


Smoking


Smoking kills about 5 million people in the world every year. This is because tobacco smoke contains lots of harmful chemicals.

✴️ Nicotine is a poison which damages the heart, blood vessels, and nerves. It is an addictive drug. Smokers cannot do without it and so find it hard to give up.

✴️Tar sticks to the insides of the lungs when smoke cools. It affects the walls of the alveoli and causes lung cancer.

✴️Carbon monoxide is a poisonous gas. It prevents blood carrying oxygen around the body. Other gases such as ammonia and cyanide irritate the insides of the air passages. This makes smokers cough.

Diseases caused by smoking


Most people who have lung cancer or cancer of the mouth are smokers.

Emphysema is caused by chemicals in tobacco smoke. Alveoli are destroyed, reducing the surface area of the lungs. Tiny hairs, (cilia) which clean the inside of the lungs, are killed by tobacco smoke. The lungs can quickly become infected by bacteria. This causes bronchitis.



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