B1e: Drugs and you

Types of Drugs

What are drugs?Drugs are substances that alter the way the body works. Some are beneficial, while others are harmful. Some drugs are only available by prescription as it may be dangerous if misused.

Addiction - physical need for drugWithdrawal symptoms - symptoms that show when you are unable to obtain the drug you are addicted toTolerance - when the body gets used to the drug and requires are higher dose of itRehabilitation - where you get help and support to try and overcome an addiction This table shows the main types of drugs and their effects on the body:

How are drugs classified?In the UK drugs are mainly classified into 3 categories- Classes A, B and C.Which class a drug is in depends on how dangerous it is - Class A drugs are the most dangerous. CLASS A drugs include heroin, LSD, ecstasy and cocaine. CLASS B drugs include cannabis and amphetamines. CLASS C drugs include anabolic steroids and tranquillisers. Using or dealing with Class A drugs is the most serious - you could get a lengthy prison sentence.Being caught using or dealing with Class C drugs will probably only get you a warning, although prison is still a possibility.In all cases, supplying drugs to others usually results in greater punishment than using it yourself.

How do stimulants and depressants affect the nervous system?Stimulants and depressants affect the synapses between neurones in the nervous system: Stimulants cause more neurotransmitter molecules to diffuse across the synapse. Depressants bind to the receptor molecules so that fewer neurotransmitter molecules are able to reach the second neuron.

Smoking

What happens when you smoke?Cigarette smoke contains many harmful chemicals. The cells lining the trachea (windpipe), bronchi and bronchioles (the branches inside the lungs) are damaged by cigarette smoke. These epithelial tissue/cells have tiny hair-like cilia on their surface. Normally these cilia move to push mucus out of the lungs. Damaged cells cannot do this, leading to a build-up of mucus and a smokers’ cough.The lungs also lose their elasticity, causing emphysema.

What problems can smoking cause? Addiction - Nicotine is the addictive substance in tobacco. It reaches the brain within 20 seconds and creates a dependency so that smokers become addicted. Smokers can suffer from withdrawal symptoms if they try to give up cigarettes. Heart disease - Carbon monoxide combines with the haemoglobin in red blood cells and so reduces the ability of the blood to carry oxygen. This puts extra strain on the circulatory system. Low birth weight babies - Smoking during pregnancy is very dangerous. It reduces the amount of oxygen available to the growing fetus. Lung, throat, mouth and oesophageal cancer - Tar from cigarettes smoke collects in lungs. It is irritant and it contains carcinogens that can mutations in DNA - causing malignant tumours. The images below compare a healthy lung and a smoker's lung:

Alcohol

What does alcohol do to your brain?The alcohol in alcoholic drinks is called ethanol. It is a depressant. This means that it slows down signals in the nerves and brain.Why are their legal limits to the level of alcohol that drivers and pilots can have in the body?This is because alcohol impairs the ability of people to control their vehicles properly. Breath tests and blood tests are used by the police to see if a driver is over the limit.

What are the short-term effects? Sleepiness Impaired judgement, balance and muscle control Blurred vision Slurred speech Increased flow of blood to the skin, which can cause it to become red. What are the long-term effects? Damage to the liver Damage to the brain due to dehydration.

How does alcohol damage the liver?The liver removes alcohol from the bloodstream. It has enzymes that break down alcohol but the products of the reactions involved are toxic. They damage the liver and over time this leads to cirrhosis.