For IGCSE O-Level Biology students Chapter 12

1. DRUGS

2. DRUGS
Stimulants
Caffeine
Nicotine
Ecstasy
Cocaine
Amphetamine
Depressants
Alcohol
Pain killers
Solvents
Heroin
Morphine
Codeine
Hallucinoge
ns
LSD
Cannabis

3. STIMULANTS

4. STIMULANTS
All stimulants increase nervous
activity.
Heart rate &wakefulness are also
increased.

5. CAFFEINE
 Present in coffee beans, tea leaves.
 It is a mild stimulant that increases
wakefulness.

6. AMPHETAMINE
 Increases alertness, decreases fatigue.
 increases blood pressure and decreases
accuracy.

7. ECSTASY
 Gives a feeling of wellbeing & increases
sociability.
 Followed by depression.
 Increases blood pressure, heart rate &
dehydration.
 Long-term use: damages brain cells.

8. COCAINE
 Gives a feeling of excitement
 Followed by depression
 It is very addictive
 Long-term use: damages arteries and
causes mental disorders

9. DEPRESSANTS

10. DEPRESSANTS
All depressants decrease nervous
activity by acting as endorphins ;our
body’s natural pain reliever.
 They suppress pain, increase relaxation,
decrease heart rate & increases reaction
time = slow responses.
 They impair judgment.
 Excessive doses inhibits breathing center
in the brain causing death.

11. ALCOHOL
 It depresses the CNS; giving a feeling of well being,
decreases anxiety, increases confidence but it decreases
the ability to do activities requiring skill and accuracy as well
as impairing judgment.
 Slows down reaction time therefore it is very dangerous to
drink and drive.
 It increases vasodilation in the skin, giving a warmer feeling
but increases heat loss.
 Large doses cause unconsciousness, breathing stops &
death.
 90% is detoxified by the liver, 10% is excreted by the kidney.
 Pregnancy: decreases baby weight; ill, deformed or still born
babies result from regular drinking.
 Long-term effects: damage of liver = cirrhosis.

12. MORPHINE, HEROIN & CODEINE.
 Morphine is a chemical extracted from part of the opium
plant.
 It is used medicinally to stop pain, especially after
surgeries.
 As well as stopping pain it increases well being and
decreases anxiety.
 Heroin & codeine are prepared by chemical reactions to
morphine.
 They are very addictive.
 Sharing needles to administer these drugs leads to blood
poisoning, hepatitis and AIDS.

13. SOLVENTS
 Sniffing glue, aerosols give a strong but short
drunkenness feeling. Dizziness and loss of
coordination is then followed by headache,
vomiting, convulsions, runny nose and blood
shot eyes.
 Large doses may lead to unconsciousness.
 Long-term use damages the kidney, liver and
brain.

14. HALLUCINOGENS

15. HALLUCINOGENS
These drugs work like brain transmitters;
altering the way you perceive things. Making
you see, hear and feel things that are not
true.

16. MARIJUANA/CANNABIS
 Was used to relieve pain before discovering
aspirin.
 Increase well being, detachment &
sometimes hallucinations
 Learning ability and memory are impaired
 Long- term effects: damages lungs, CNS,
immunity & reproductive system. It
decreases sperm count and sexual drive in
males.

17. LSD
 Cause distorted vision, sound, sometimes
strong nightmarish hallucinations that
sometimes lead to lethal accidents.

18. ALL DRUGS
 Interfere with brain function
 Damage the body
 Cause tolerance: a larger dose is needed to
get high.
 Causes dependence or addiction
 Cause withdrawal symptoms that range from
cravings, to nausea, sickness, muscular
pain, uncontrollable shaking & hallucinations.

19. COMPARING DEPENDENCE AND ADDICTION OF VARIOUS DRUGS

20. SOCIAL IMPLICATIONS OF DRUG ABUSE
 Loss of jobs
 Spending all money to support the habit
 Destruction of family life
 Loss of interest in appearance and hygiene
 Addicts become involved in criminal activity
to fund their habit