'Drunkenness, in its most common usage, is the state of being intoxicated with alcohol to a sufficient degree to impair mental and motor functioning.
Some societies, such as those of Russia and Ireland, have cultural stereotypes associated with drunkenness--in such societies, the ability to drink vast quantities of alcohol without getting drunk is thought to be worthy of respect. Arguably, such an attitude, wherever it does in fact exist, can be regarded as pathological, leading as it often does to alcoholism.
Drunkness is generally felt to be a good thing by the drunk person, at least till it wears off, and the associated hangover starts.
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 to taking in large amounts on an empty stomach. This is because the presence of food in the stomach is able to slow the absorption of alcohol in to the bloodstream, diluting its effects 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 relationship 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 unconscioussness can often occur, and in extreme cases (when the concentration of alcohol in the bloodstream is over about 500mg per 100ml) alcohol can even cause death.
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 the relaxative state it puts the body into. This could be caused by heightened alpha brain waves surging across the brain. Alpha waves are observed (with the aid of ECGs) when the body is relaxed. Heightened pulses are thought to correspond to higher levels of enjoyment.
A well-known side effect of alcohol is the loosening it has on inhibitions. Alcohol makes neurons (brain nerve cells) much more permeable. This enables sodium ions, present in axons sprouting from nerve cells, to pass more easily out of cell membranes, negatively affecting the function of these cells. 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.
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 systen 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 per cent less glucose than it should. With less glucose metabolism, the cells work less efficiently and aren't able to process what we see properly.
Often after lots of alcohol has been consumed, it is possible to get the sense that the room is spinning, technically called 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, 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 cupola, which moves when the body moves. This brushes against hairs in the ear, creating nerve impulses that travel through the 8th Cranial Nerve 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 tell your 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.
Slang terms for being drunk:
- liquored up