Tuesday, 9 December 2014

#19 Drugs (English)


Drugs


What are drugs?

We can define a drug as a substance taken into the bod that modifies or effects chemical reactions in the body. When most people hear the word ‘drug’ they automatically think of substances like cocaine or heroin. Yes, those are drugs however there are four different types of drugs; stimulants, depressants, painkillers and hallucinogens.

What are stimulants?
Stimulants are substances that increase brain activity. This includes nicotine, caffeine and ecstasy. Some short term effects are exhaustion, apathy and the depression that follows the original high. It is this immediate and lasting exhaustion that leads the user to want the drug again. This can lead to addiction. Stimulants also have long term effects. Repeated high doses of some stimulants over a short period of time can lead to feelings of hostility or paranoia.

What are depressants?
Depressants do the opposite of stimulants by slowing down brain activity. The most common example of a depressant is alcohol. Short term effects include slow pulse and breathing, lowered blood pressure, poor concentration, confusion, fatigue, disorientation, slurred speech, fever and addiction. Higher doses can cause impairment of memory, irritability, paranoia, and suicidal thoughts. However, some people experience the opposite of the intended effect, such as agitation or aggression. Depressants have many long term effects too. Tolerance to many depressants can develop rapidly, with larger doses needed to achieve the same effect. The user, trying to reach the same high, may raise the dose to a level that results in coma or death by overdose. As a dependency on the drug increases, cravings, anxiety or panic are common if the user is unable to get more. When the user tries to get off the drug withdrawal symptoms include insomnia, weakness and nausea.

What are painkillers?
Painkillers block nerve impulses and in addition to this can also produce a high. The most powerful painkillers are called opioids. The most commonly abused opioid painkillers include oxycodone, hydrocodone, meperidine, hydromorphone and propoxyphene. Oxycodone is as powerful as heroin and affects the nervous system the same way. Hydrocodone is used in combination with other chemicals and is available in prescription pain medications as tablets, capsules and syrups. Meperidine (Demerol) and hydromorphone (Dilaudid) come in tablets and propoxyphene (Darvon) in capsules, but all three have been known to be crushed and injected, snorted or smoked.

What are hallucinogens?
Hallucinogens alter what we hear and see such as cannabis or LSD. Almost all hallucinogens contain nitrogen and are classified as alkaloids. Many hallucinogens have chemical structures similar to those of natural neurotransmitters. While the exact mechanisms by which hallucinogens exert their effects remain unclear, research suggests that these drugs work, at least partially, by temporarily interfering with neurotransmitter action or by binding to their receptor sites.

 
Drug classification
Some drugs are legal while others are illegal, or must only be prescribed by a doctor. Some prescription drugs are mistreated and taken for recreational use, rather than for medical reasons. They become illegal under these circumstances. Illegal drugs are classified from Class A to Class C. Class A drugs are the most dangerous, with the most serious penalties for possession or dealing. Class B drugs are the second most dangerous and class C are the least dangerous, with the lightest penalties, but this does not mean they are safe to use. 

Alcohol
As you now know alcohol is a depressant as it slows down the activity of the brain. In some countries drinking alcoholic drinks is common while in others it is forbidden. Alcohol is quickly absorbed through the walls of the stomach and is then quickly transported all over the body in the blood. When it reaches the brain it slows down reflex reactions by reducing the rate at which neurons can conduct nerve impulses and pass them from one neuron to another. This is why drinking and driving is highly forbidden since drivers are unable to respond quickly. A very high proportion of injuries and deaths come from car accidents where the driver has been drinking.

Smoking

The image shows the comparison of healthy lungs to lungs of those who smoke. Cigarette smoke is made of nicotine, tar, particulates and carbon monoxide. The nicotine is what makes smoking addictive. It affects the brain and makes people feel more relaxed. As well as this it affects the circulatory system by increasing the rate at which the heart beats and increasing blood pressure. People who smoke are more likely to suffer from heart disease than non-smokers. Tar in cigarette smoke can cause cancer. The chemicals in tar affect the cells that line the passage ways leading to the lungs, and also the cells in the lungs themselves. This may cause the cells to lose the ability to control their division which results in uncontrollable division forming a lump called a tumor which can cause cancer. Tar and carbon monoxide also affect the cilia and goblet cells that line the trachea and the bronchi. The carbon monoxide causes the cilia to stop working and in a heavy smoker the cilia may completely disappear. The smoke makes the goblet cells work harder producing more and more mucus and as there are no cilia to sweep it up the mucus trickles down into the lungs where it collects, making the person cough. The constant coughing can damage the delicate walls of the alveoli which eventually break down preventing oxygen from easily diffusing from the alveoli to the blood. Particulates cause irritation since they aren’t stopped by the malfunctioning cilia leading to more damage of the alveolar walls.  

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