Effects Alcohol has on:

Central Nervous System

The major acute effect of alcohol on the central nervous system is that of a depressant. Alcohols depressant actions dis-inhibits many higher cortical functions which place a brake on various actions.Through the depressant effects of alcohol, parts of the brain are released from their normal inhibitory restraints. This behavior that would normally be censured or inhibited can occur.

Ingestion

When ingested alcohol passes from the stomach into the small intestine where it is rapidly absorbed into the blood and distributed throughout the body. As blood alcohol concentration increases, a person's response to stimuli decreases, speech becomes slurred, movements are unsteady. With very high concentrations - greater than 0.35 grams/100 milliliters of blood (equivalent to 0.35 grams/210 liters of breath ) - a person can become comatose and die.

Liver

Alcohol can lead to rapid accumulation of fat in liver cells. Alcohol can interfere with the normal liver function of maintaining a steady, adequate supply of blood sugar.Alcohol can block a complicated maneuver called gluconeogenesis (a biochemical process that transforms other nutrients, such as protein, into glucose). Which could cause hyperglycemia ( abnormally high levels of blood glucose).

Kidneys

Alcohol causes the posterior portion of the pituitary gland located at the base of the brain to secrete a hormone called ADH ( antidiuretic hormone) that regulates the amount of water the kidneys excrete. When the pituitary is affected by alcohol, it's functioning is depressed. Therefore, too little of the hormone is released, and the kidneys produce a larger than normal amount of dilute urine.

Digestive System

Alcohol is known as an irritant. This is why in most cases when it is consumed you feel a burning sensation.

Circulatory System

In moderate amounts alcohol is a vasodilator of surface blood vessels. The vessels near the skin surface expand which accounts for the sensation of warmth and flush to the skin that accompany drinking. Despite the subjective feeling of warmth, body heat is lost.

Breakdown

The breakdown or metabolism of alcohol occurs in a multi-step process. The first step is called biochemical conversion to acetaldehyde. The enzyme that accomplishes this is called alcohol dehydrogenase, referred to as ADH. The breakdown of alcohol that occurs in the stomach is termed "first pass metabolism." A history of chronic heavy alcohol use leads to a significant decrease in first pass metabolism.

Removal

The removal of alcohol from the body begins as soon as the alcohol is absorbed into the bloodstream.

Blood Alcohol Concentration

With high concentrations of alcohol the pyloric valve( controls the passage of stomach contents into the small intestine) gets stuck in the closed position a condition called pylorospasm. When pylorspasm occurs the alcohol trapped in the stomach may cause sufficient irritation and distress to induce vomiting.

Absorption

absorption of alcohol begins almost immediately with a very small amount taken up into the bloodstream through the tiny blood vessels in the mouth. 20% can be absorbed directly from the stomach, and another small portion is metabolized in the stomach. The remainder passes into the small intestine to be absorbed.