If you have ever seen a person who has had too much to drink, you know that alcohol is a drug that has widespread effects on the body, and the effects vary from person to person. People who drink might be the "life of the party" or they might become sad and droopy. Their speech may slur and they may have trouble walking. It all depends on the amount of alcohol consumed, a person's history with alcohol and a person's personality.
Even though you have seen the physical and behavioral changes, you might wonder exactly how alcohol works on the body to produce those effects. What is alcohol? How does the body process it? How does the chemistry of alcohol work on the chemistry of the brain? In this article, we will examine all of the ways in which alcohol affects the human body.
What is Alcohol?
In order to understand alcohol's effects on the body, it is helpful to understand the nature of alcohol as a chemical, so let's take a look...
Here are several facts
Alcohol is a clear liquid at room temperature. Alcohol is less dense and evaporates at a lower temperature than water (this property allows it to be distilled -- by heating a water and alcohol mixture, the alcohol evaporates first). Alcohol dissolves easily in water. Alcohol is flammable (so flammable that it can be used as a fuel).
You will not find pure alcohol in most drinks; drinking pure alcohol can be deadly because it only takes a few ounces of pure alcohol to quickly raise the blood alcohol level into the danger zone.
How Alcohol Enters the Body
When you compare men and women of the same height, weight and build, men tend to have more muscle and less fat than women. Because muscle tissue has more water than fat tissue , a given dose or amount of alcohol will be diluted more in a man than in a woman. Therefore, the blood alcohol concentration resulting from that dose will be higher in a woman than in a man, and the woman will feel the effects of that dose of alcohol sooner than the man will.
When a person drinks an alcoholic beverage, about 20 percent of the alcohol is absorbed in the stomach and about 80 percent is absorbed in the small intestine. The concentration of alcohol in the beverage - The greater the concentration, the faster the absorption.
How the Body Responds to Alcohol
Alcohol acts primarily on the nerve cells within the brain. Alcohol interferes with communication between nerve cells and all other cells, suppressing the activities of excitatory nerve pathways and increasing the activities of inhibitory nerve pathways.
How Nerve Cells TalkNerve cells talk to each other and to other cells (such as muscle or gland cells) by sending chemical messages. These messages are called neurotransmitters.
An electrical signal travels down one nerve cell, causing it to release the neurotransmitter into a small gap between cells called the synapse. The neurotransmitter travels across the gap, binds to a protein on the receiving cell membrane called a receptor, and causes a change (electrical, chemical or mechanical) in the receiving cell. The neurotransmitter and receptor are specific to each other, like a lock and key . Neurotransmitters can either excite the receiving cell to cause a response or inhibit the receiving cell from stimulation.
Alcohol affects various centers in the brain, both higher and lower order. The centers are not equally affected by the same BAC -- the higher-order centers are more sensitive than the lower-order centers. As the BAC increases, more and more centers of the brain are affected.The order in which alcohol affects the various brain centers is as follows
1. Cerebral cortex
2. Limbic system
3. Cerebellum
4. Hypothalamus and pituitary gland
5. Medulla (brain stem)
Alcohol's Effects on Other Body Systems
In addition to the brain, alcohol can affect other body tissues. It has the following effects on other systems in the body:Irritates the linings of the stomach and intestine - This can lead to vomiting.Increases blood flow to the stomach and intestines - This increases secretions by these organs, most notably stomach acid secretion.
Increases blood flow to the skin - This causes a person to sweat and look flushed. The sweating causes body heat to be lost, and the person's body temperature may actually fall below normal.Reduces blood flow to muscles - This can lead to muscle aches, most notably when a person recovers from the alcohol (the "hangover").
All of alcohol's effects continue until the ingested alcohol is eliminated by the body.
The normal chemical and electrical functions of nerve cells increase to compensate for the inhibitory effects of alcohol exposure. This increased nerve activity helps people to function normally with higher BAC; however, it also makes them irritable when they are not drinking. Furthermore, the increased nerve activity may make them crave alcohol. Most certainly, the increased nerve activity contributes to hallucinations and convulsions ( e.g. delirium tremens) when alcohol is withdrawn, and makes it difficult to overcome alcohol abuse and dependence.
Long-term Effects
In addition to the adaptations mentioned on the previous page, there are many adverse physical effects that result from long-term exposure to alcohol.
The increased activity in the liver causes cell death and hardening of the tissue (cirrhosis of the liver).
The brain cells in various centers die, thereby reducing the total brain mass. Stomach and intestinal ulcers can form because the constant alcohol use irritates and degrades the linings of these organs. Blood pressure increases as the heart compensates for the initially reduced blood pressure caused by alcohol. Male sex-cell (sperm) production decreases because of decreased sex-hormone secretion from the hypothalamus/pituitary and, possibly, direct effects of alcohol on the testes. Poor nutrition decreases levels of iron and vitamin B, leading to anemia. Because alcoholics lose balance and fall more often, they suffer more often from bruises and broken bones; this is especially true as they get older.
Finally, alcohol abuse and dependence cause emotional and social problems. Because alcohol affects emotional centers in the limbic system, alcoholics can become anxious, depressed and even suicidal. The emotional and physical effects of alcohol can contribute to marital and family problems, including domestic violence, as well as work-related problems, such as excessive absences and poor performance.
While alcoholism has devastating effects on a person's health and social environment, there are medical and psychological ways to treat the problem. It's no secret that intoxication has a number of immediate negative consequences. Among other things, it impairs judgement, it impairs the ability to do most things and it can bring on a depressed mood. But even after a drinker has sobered up, alcohol can still be causing the body trouble. More than 75 percent of alcohol consumers have experienced a hangover at least once; 15 percent have one at least every month; and 25 percent of college students feel symptoms weekly.
What is a Hangover?
The formal name for a hangover is veisalgia, from the Norwegian word for "uneasiness following debauchery" (kveis) and the Greek word for "pain" ( algia) -- an appropriate title considering the uncomfortable symptoms experienced by the average drinker.
Headache Poor sense of overall well-being Sensitivity to light and sound Diarrhea Loss of appetite Trembling Nausea Fatigue Increased heart rate and blood pressure Dehydration (dry mouth, extreme thirst, dry eyes) Trouble concentrating Anxiety Difficulty sleeping Weakness
The most common symptoms are headache, fatigue and dehydration, and the least common is trembling. The severity and number of symptoms varies from person to person; however, it is generally true that the more alcohol a drinker consumes, the worse the hangover will be.It usually takes five to seven cocktails over the course of four to six hours to cause a hangover for a light-to-moderate drinker (a man who drinks up to three alcoholic beverages a day or a woman who drinks up to one).
It may take more alcohol for heavier drinkers because of increased tolerance. Other than the number of drinks consumed, hangovers can be made worse by - drinking on an empty stomach, lack of sleep, increased physical activity while drinking (for example dancing), dehydration before drinking, poor health.
