1. Drugs and how they
work

2. What are drugs
A drug is any substance that is taken into the body
that alters or influences chemical reactions in the
body.

3. Types of drugs
Medical drugs
These drugs are designed to suppress pain
, counteract the symptoms of flue or kill
pathogenic bacteria
Aspirin
Paracetamol
Morphine
Antibiotics

4. Types of drugs
Hallucinogens
These drugs cause psychedelic visions for the drug
user.
Lysergic Acid Diethylamide or LCD

5. Types of drugs
Stimulants
These are mood-enhancing drugs which give the
user a short-lived feeling of wellbeing and energy.
Examples
Cocaine , ecstasy and amphetamines.

6. Types of drugs
Depressants (downers)
Slow down the brain and central nervous system.
Examples are alcohol, beer, wine, vodka, gin etc
heroin, tranquilizers, sleeping pills

7. Drugs in the body
Drugs such as nicotine and heroin , interfere with
the way that the nervous system works.
Mood-enhancing drugs, such as heroin and
nicotine act at synapses in the nervous system and
change the way in which neurons send impulses.
Drugs are broken down in the body by enzymes
and the products are excreted.

8. Drug addiction
Many drugs have the potential to be addictive. If the body
comes to rely on the drug a person can become addicted
and feel the need to take it regularly.
The body’s metabolism may become used to the drug.
The liver may produce more enzymes to break it down so
that the dose of the drug has to increase to have the
same effect the user first experienced.

9. Drug tolerance
in the case of heroin, synapses may produce more
target molecules and if these do not combine with
heroine this leads to an increase in the feeling of
pain.
The person has become dependent on the drug
and cannot survive without it.
When the people stop taking the drug they may
experience withdrawal symptoms which can vary
from nausea to severe cramp.

10. Antibiotics
Antibiotics are a group of chemicals made by
microorganisms (bacteria and fungi) that are used
in chemotherapy as they kill pathogens or stop
their growth.
Antibiotics destroy pathogens by disrupting cell
wall formation, inhibiting protein synthesis and
metabolism in the pathogen cell.

11. Antibiotics
Antibiotics cannot kill viruses since they have no
cell wall and live inside host cell, taking over their
metabolic processes.

12. HEROIN
Biology of heroin
Heroine is a compound modified from morphine.
Heroine is a powerful depressant that slows down the
nervous system.
Heroine resembles the natural body’s
painkillers, known as a natural opiate.
First time users experience euphoria- feeling of
contentment and intense happiness.

13. Addiction to heroin
Heroin becomes part of the body’s metabolism and
the body quickly gets used to the drug.
More painkillers are needed to prevent them
sending impulses to the brain. But the body does
not produce more of its own natural painkillers.

14. Social problems
Heroin addicts may turn to crime to obtain money for their
next dose.
Shared needles have resulted in the spread hepatitis and
HIV amongst addicts who inject heroin.
A user who stops taking the drug experiences very un
pleasant withdrawal symptoms. These can include
sleeplessness and hallucinations, muscle
cramps, sweating, vomiting and nausea.

15. Alcohol
Biology of alcohol
Alcohol is absorbed into the blood very quickly since
it is small molecule that does not need to be digested
It is absorbed by liver cells and broken down by
enzymes so that its concentration in the blood
decreases gradually.
Alcohol is a depressant. It affects the brain by
slowing down the transition of nerve impulses.

16. Social problems of alcohol
Crime , family disputes, marital breakdown, child
neglect and abuse, absenteeism from
work, vandalism, violent crime including murder.
Alcohol and other drugs are involved in many road
accidents.

17. Long-term effects of alcohol
Stomach ulcers, heart disease and brain damage.
If heavy drinking continues then the liver becomes
full of nodules. This is the condition known as
cirrhosis.

18. Smoking and health
components of tobacco
smoke
Biology of tobacco smoke
Nicotine
It is absorbed very quickly through the alveoli to enter
the bloodstream. Nicotine makes the heart beat faster
and narrows the arterioles.
- Tar
Is a black sticky material that collects in the lungs as a
smoke cools. Tar irritates the lining of the airways and
stimulates them to produce more mucus.

19. Components of tobacco
smoke
Carbon monoxide
This is a poisonous gas. It is absorbed by
hemoglobin in red blood cell.
It reduces the volume of oxygen that blood can carry.

20. Diseases caused by smoking
Chronic bronchitis and emphysema
The bronchi become blocked as there is less space
for air to flow. Large amounts of mixture of
mucus, bacteria and white blood cells are
produced, which people attempt to cough up.
The break down of alveoli becouse of partcles
bacteria and tar , reducing gas exchange is called
emphysema.

21. Diseases caused by smoking
Lung cancer
Heart desease

22. Questions ??