Can you tell which number will be placed in the blank?
What are drugs?
A drug is a substance, natural or
artificial that alters the function of
the body
.
Effects of Drugs
Drugs affect a person's body in many different ways.
Discuss with your partner how can drugs affect the
nervous system.
Drugs affect the nervous system in one or more of the
following ways:
● can cause an increase in the amount of a neurotransmitter
that is released into a synapse.
● can block a receptor site on a dendrite, preventing a
neurotransmitter from binding.
● can prevent a neurotransmitter from leaving a synapse.
● can imitate a neurotransmitter.
Draw conclusions
What conclusions do you draw from the information?
Many drugs that affect the nervous system influence the
level of a neurotransmitter called Dopamine. Dopamine is
the neurotransmitter found in the brain that is involved
with
the
control
of
body
movement
and
functions.Dopamine is strongly involved with the feelings
of pleasure or reward.
Normally, dopamine is removed from a synapse by being
reabsorbed by the neuron that released it.As seen in the
figure above.
Classes of Commonly Abused Drugs
Stimulants
Drugs that increase alertness and physical activity
Nicotine: increase amount of dopamine released in the
synapse.constricts blood vessels,raises BP causing heart
to work harder than normal.
Caffeine:
It works by binding to adenosine receptors on
neurons in the brain.Adenosine slows down neural
activity causing drowsiness.When caffeine binds to
these receptors. It has the opposite effect. It
temporarily raises adrenaline levels in your body
giving a quick burst of energy that soon wears off.
Depressants
Drugs that tend to slow down the central nervous system.
Alcohol:
It is a depressant. It affects at least 4 different
neurotransmitters resulting in a feeling if relaxation and
sluggishness.Consumption of alcohol in pregnancy is the
cause of fetal alcohol syndrome which can result in
damage to baby’s brain and nervous system.
Depressants
Inhalants: They are chemical fumes, work by acting as
depressant on CNS. generally have a short term effect of
intoxication as well as nausea and vomiting. Death can
occur.Long exposure can cause memory loss, hearing
loss,vision problems,PNS damage and brain damage.
Illegal drugs
Amphetamines and cocaine both increase dopamine levels and both prevent
dopamine from being reabsorbed, so it remains in the synapses. This
ultimately increases the levels of dopamine in the brain and results in the
feeling of pleasure and well being.
Their use of cocaine and amphetamines has short term and long term effects.
Cocaine abuse might result in disturbances in heart rhythm, heart attacks,
chest pain, respiratory failure strokes, seizures, headaches etc.
Abuse of amphetamines might result in rapid heart rate, irregular heartbeat,
increased BP and irreversible stroke producing damage to small blood vessels.
Illegal Drugs
Abusers can experience episodes of violent behavior, paranoia, anxiety,
confusion and insomnia.
Marijuana active chemical ois Tetrahydrocannabinol. Smoking it quickly gets
THC into the bloodstream where it is carried to the brain.THC binds to
receptors on neurons in the brain producing the effect of intense pleasure.
Short term effects include problems with memory and learning, loss of
coordination, increased heart rate, anxiety,, paranoia and panic attacks. Long
term might cause lung cancer.
Tolerance and Addiction
Tolerance occurs when a person needs more
and more of the same drug to get the same
effect.
The psychological and/or physiological
dependence on a drug is addiction
Treatment
People who are either psychologically or physiologically dependent on drugs
experience serious withdrawal symptoms. Medical supervision , counselling,
clergy , social workers,nurses, doctors etc are all support services.
Connect to your own life:
What’s something interesting
you learned today?
Can you relate this to
something in your own life?
(How is it similar, different, or helpful
to events in your life?)