Science Fair Project Encyclopedia
Drunkenness, in its most common usage, is the state of being intoxicated with alcohol (i.e. ethanol) to a sufficient degree to impair mental and motor functioning.
Effects of alcohol on the body
Alcohol is a potent drug and consequently it has a range of side effects, some pleasurable and some less so. The amount consumed and the circumstances under which the alcohol was taken can play a large part in determining the extent of drunkenness. Drinking after eating a large meal is much less likely to induce drunkenness compared with drinking on an empty stomach. This is because the presence of food in the stomach is able to slow the absorption of alcohol into the bloodstream, spreading its effect over a longer period of time.
Cell membranes are highly permeable to alcohol, so once alcohol is in the bloodstream it can diffuse into nearly every tissue of the body. This can contribute to the correspondingly dramatic effect seen when large amounts are taken.
Alcohol has a biphasic effect on the body - its effects transform over an evening of drinking, from initial feelings of relaxation and cheerfulness to blurred vision and problems with coordination. After excessive drinking, unconsciousness can occur and in extreme cases (when the concentration of alcohol in the bloodstream is over 0.5 percent) alcohol can even cause death. Death can also be caused by asphyxiation (choking) as a result of vomit blocking the trachea. An appropriate first aid response to an unconscious, drunken person is a maneuver known as the recovery position.
Sometimes, people in such altered states act irresponsibly because of reduced inhibitions. The term intoxication is typically used in legal proceedings when some crime has been committed during a state of intoxication.
Although alcohol is commonly thought of purely as a depressant, at low concentrations it can actually stimulate certain areas of the brain. Alcohol sensitises the N-methyl-D-aspartate (NMDA) system of the brain, making it more receptive to the neurotransmitter glutamate. Stimulated areas include the cortex, hippocampus and nucleus accumbens, which are responsible for thinking and pleasure seeking. Another one of alcohol's agreeable effects is body relaxation, possibly caused by heightened alpha brain waves surging across the brain. Alpha waves are observed (with the aid of EEGs) when the body is relaxed. Heightened pulses are thought to correspond to higher levels of enjoyment.
A well-known side effect of alcohol is lowering inhibitions. Areas of the brain responsible for planning and motor learning are dulled. A related effect, caused by even low levels of alcohol, is the tendency for people to become more animated in speech and movement. This is due to increased metabolism in areas of the brain associated with movement, such as the nigrostriatal pathway. This causes reward systems in the brain to become more active, and combined with released inhibition can induce people to behave in an uncharacteristically loud and cheerful manner.
Behavioural changes associated with drunkenness are, to some degree, contextual. A scientific study found that people drinking in a social setting significantly and dramatically altered their behaviour immediately after the first sip of alcohol, well before the chemical itself could have filtered through to the nervous system. Likewise, people consuming non-alcoholic beer or "shirley temple" mixed drinks have been observed exhibiting increasingly drunk-like behavior on a par with their alcohol drinking companions even though their own drinks contained no alcohol whatsoever.
The effect alcohol has on the NMDA receptors, earlier responsible for pleasurable stimulation, turns from a blessing to a curse later in the evening if further alcohol is consumed. NMDA receptors start to become unresponsive, slowing thought in the areas of the brain they are responsible for. Contributing to this effect is the activity which alcohol induces in the gamma-aminobutyric acid system (GABA). The GABA system is known to inhibit activity in the brain, and would cause other areas to slow down. GABA could also be responsible for the memory impairment that many people experience. It has been asserted that GABA signals interfere with the registration and consolidation stages of memory formation . As the GABA system is found in the hippocampus, which is thought to play a large role in memory formation, this is thought to be possible.
Blurred vision is another common symptom of drunkenness. Alcohol seems to suppress the metabolism of glucose in the brain. The occipital lobe, the part of the brain responsible for interpreting vision, has been found to become especially impaired, consuming 29 percent less glucose than it should. With less glucose metabolism, the cells work less efficiently and aren't able to process images properly. Severe drunkenness and diabetic coma can be mistaken for each other, with potentially serious medical consequences for diabetics.
Often, after a lot of alcohol has been consumed, it is possible to get the sense that the room is spinning, a type of nystagmus referred to as positional alcohol nystagmus . Although motor areas of the brain are usually heavily affected at this time, it is not directly the brain which is responsible here; alcohol has affected the organs responsible for balance (vestibular system), present in the ears. Balance in the body is monitored principally by two systems: the semicircular canals, and the utricle and saccule pair. Inside both of these is a flexible blob called a cupula , which moves when the body moves. This brushes against hairs in the ear, creating nerve impulses that travel through the vestibulocochlear nerve (Cranial nerve VIII) in to the brain. However, when alcohol gets in to the bloodstream it distorts the shape of the cupola, causing it to keep pressing on to the hairs. These 'fake' nerve impulse tells the brain that the body is rotating, causing disorientation and making the eyes spin round to compensate. When this wears off (usually taking until the following morning) the brain has adjusted to the spinning, and interprets not spinning as spinning in the opposite direction causing further disorientation. This is often a common symptom of the hangover.
A person who is an alcoholic or habitually drunk is often referred to as a 'drunk', or, more traditionally, a 'drunkard'.
Many societies have cultural stereotypes associated with drunkenness - where the ability to drink vast quantities of alcohol is thought to be worthy of respect. Arguably, such an attitude can be regarded as pathological, leading as it often does to alcoholism.
Drunkenness is generally felt to be a good thing by the drunk person, at least until it wears off and the associated hangover starts.
The Ancient Greeks believed that putting a piece of amethyst in the glass or in one's mouth while drinking prevented drunkenness, although this usage may be related to a play on words (Ancient Greek: "a-methyst" meaning "not intoxicated"). This also works in the game of Nethack.
Many religions discourage or prohibit alcohol consumption. The Qur'an, or book of Islam, declares that God prohibits the consumption of alcohol by humankind, because of harmful effects for the body, harmful effects for the consumer's life and family, social problems, and distraction from mindfulness of God.
- Alcoholic beverages
- Beer goggles (slang)
- Blind drunk
- List of slang terms for drunkenness
- Pub crawl
- Stuart Walton: Out of It. A Cultural History of Intoxication (Penguin Books, 2002) (ISBN 0140279776).
- 'Modern Drunkard Magazine', A humorous magazine about drink and the art of getting drunk.
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