How Drugs & Alcohol Work

How Drugs Work

 Homeostasis – maintenance of an environment of body functions within a certain range.


Ψ  All nervous systems consist of specialized nerve cells called neurons

Ψ  Neurons are responsible for receiving and sending information

Ψ  Sending and receiving information is  highly specialized, precise and very rapid

Ψ  The receiving region of the neuron is affected by a chemical message that either excites or inhibits

Ψ  If the message is excitatory, an impulse moves from the receiving region of the neuron down the axon to the sending  region, the terminal, and chemical messengers, neurotransmitters, are released

The Nervous Systems:

Ψ Somatic Nervous System

o   Sensory information

o   Voluntary actions

Ψ The Autonomic Nervous System (ANS)

o   Sympathetic

o   Parasympathetic

Ψ The Central Nervous System

o   The Brain

o   Chemical Pathways



Brain Imaging Techniques

Ψ PET-Position Emission Tomography

Ψ MRI- Magnetic Resonance Imaging


1. Alcohol is a psychoactive drug that is a CNS depressant – the second most abused psychoactive drug.

2. Measured in proof

3. Alcohol is often looked at as a non-drug

a. 1700’s alcohol preferred over water

b. Puritans – “Good Creature of God”

c. Post revolution – alcohol problem

d. 780’s introduced idea of addiction – Temperance Movement to Prohibition

Who Drinks and Why

          Cultural influences –

                   Russians/Irish – heavy drinkers

French drink with meals – consume more alcohol than any other nation

                   Czechs world’s leading beer drinkers – Ireland, Germany and Austria

                   Gender Differences – males drink more alcohol than females


Physiological Effects of Alcohol

          Brain: 1-2 drinks affect the outer brain – dis-inhibition, euphoria, relaxation (.05 BAC)

 3 + drinks – affect the cerebellum – coordination, perception and memory blackouts; midbrain – reflexes, stupor,

                   coma; medulla – lowered heart rate and breathing death; long term use decreases brain tissue – alcoholic

                   dementia; teenage brain – underdeveloped prefrontal cortex

          Heart: cholesterol; blood pressure

                             Increased calories – obesity / diabetes


                             Cardiac arrhythmia / cardiac death

          GI tract: stomach – increased acid

          Cancer: mouth / esophagus / stomach / intestines 

          Liver: ALD – fatty liver/ alcohol hepatitis/ cirrhosis/ liver cancer

          Reproductive system: decreased testosterone; lowered function and size;

decreased fertility in women

          Immune system: increased breast cancer, blood pressure, diabetes, kidney disease, acne

Psychological Effects of Alcohol

             Increased BAC increases effects of blackouts; increased sexual behavior; crime and violence

Alcohol Dependence

          Withdrawal Syndrome

1. Tremors, rapid heartbeat, heavy sweating, appetite loss, insomnia

2. Hallucinations

3. Delusions

4. Seizure activity


Progressive Effects of Alcohol

Blood Alcohol Concentration

Changes in Feelings and Personality

Brain Regions Affected

Impaired Activities (continuum)



Sense of wellbeing
Loss of inhibition

Cerebral cortex



(especially fine motor skills)

Visual tracking

Reasoning and depth perception

Inappropriate social behavior
(e.g., obnoxiousness)

Slurred speech

Lack of balance

Loss of temperature regulation

Loss of bladder control

Difficulty breathing

Slowed heart rate


Numbness of feelings
Nausea, Sleepiness
Emotional arousal

Cerebral cortex +



Mood swings

Cerebral cortex +
forebrain +



Reduced sensations

Cerebral cortex +
forebrain +
cerebellum +
brain stem



Death possible

Entire brain


0.41 and greater





Amount of Alcohol and the Effect on Body Weight




Beverage intake



100 lb


100 lb


150 lb


150 lb


200 lb


200 lb


1 oz spirits

1 glass wine

1 can beer 








2 oz spirits

2 glasses wine

2 cans beer








4 oz spirits

4 glasses wine

4 cans beer 








6 oz spirits

6 glasses wine

6 cans beer 








8 oz spirits

8 glasses wine

8 cans beer








10 oz spirits

10 glasses wine

10 cans beer







Alcoholism symptoms include:

      Being unable to limit the amount of alcohol you drink

      Feeling a strong need or compulsion to drink

      Developing tolerance to alcohol so that you need an increasing amount to feel its effects

      Having legal problems or problems with relationships, employment or finances due to drinking

      Drinking alone or in secret

      Experiencing physical withdrawal symptoms — such as nausea, sweating and shaking — when you don't drink

      Not remembering conversations or commitments, sometimes referred to as "blacking out"

      Making a ritual of having drinks at certain times and becoming annoyed when this ritual is disturbed or questioned

      Losing interest in activities and hobbies that used to bring you pleasure

      Irritability when your usual drinking time nears, especially if alcohol isn't available

      Keeping alcohol in unlikely places at home, at work or in your car

      Gulping drinks, ordering doubles, becoming intoxicated intentionally to feel good or drinking to feel "normal"

People who abuse alcohol may have many of the same signs and symptoms as people who have full-blown alcoholism.  However, if you abuse alcohol but aren't completely addicted to it, you may not feel as much of a compulsion to drink.  You may not have physical withdrawal symptoms when you don't drink.  Yet, alcohol abuse can still cause serious problems.  As with alcoholism, you may not be able to quit drinking without help.

If you've ever wondered whether your drinking crosses the line into alcohol abuse or dependence, ask yourself these questions:

      If you're a man, do you ever have five or more drinks in a day?  One standard drink is equivalent to 12 ounces (354.9

         milliliters) of beer, 5 ounces (147.9 milliliters) of wine or 1.5 ounces (44.4 milliliters) of 80-proof spirits.

      If you're a woman, do you ever have four or more drinks in a day?

      Do you need a drink as soon as you get up?

      Do you feel guilty about your drinking?

      Do you think you need to cut back on how much you drink?

      Are you annoyed when other people comment on or criticize your drinking habits?

If you answered yes to even one of these questions, you may have a problem with alcohol.

When to see a doctor

If you feel that you don't have control over your drinking, talk with your doctor. See your doctor even if you don't think you have alcoholism, but you're concerned that you might be drinking too much or that alcohol may be causing problems in your life.  Other ways to get help include talking with a mental health provider or seeking help from a support group such as Alcoholics Anonymous.

Because denial is a frequent characteristic of alcohol abuse and alcoholism, you may not feel like you need treatment.  You might not recognize how much you drink or how many problems in your life are related to alcohol use.  Listen to family members, friends or co-workers when they ask you to examine your drinking habits or to seek help.

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