Drugs and the Nervous System
Drugs
• Drug – any substance, other than food, that
changes the structure or function of the body.
• all drugs whether legal or illegal have the
potential to do harm if used improperly or
abused
Drugs that affect the synapse
• Synapses are key relay stations for your
nervous system
• Your nervous system needs neurotransmitters
to bridge the gap between neurons
• Drugs that interfere with the
neurotransmitters disrupt the functioning of
your nervous system.
Stimulants
• Stimulants – increase the actions regulated by
the nervous system
• Effects: increase heart rate, blood pressure
and breathing rate. Increase release of
neurotransmitters at some synapses in the
brain
• Leads to a feeling of energy and well-being
• When it wears off, you feel fatigue and
depression
• Long term use can cause circulatory problems,
hallucinations, and depression
Depressants
• Depressants – decrease the rate of functions
regulated by the brain
• Effects: slow down heart rate and breathing
rate, lower blood pressure, relax muscles, and
relieve tension
• Some depressants can enhance the effects of
neurotransmitters that prevent nerves from
starting action potentials
• This calms down the parts of the brain that
sense fear and relaxes the individual
• People can become depended on these drugs
to get through the stresses of everyday live
Cocaine
• Cocaine causes the sudden release in the brain of
neurotransmitter call dopamine
• The release of large amounts dopamine produces
an intense feeling of pleasure and satisfaction.
• When the effects wear off the amount of
dopamine is depleted and leaves the user feeling
sad and depressed
• Cocaine also acts like a powerful stimulant,
increases heart rate and blood pressure
• Crack is a form of cocaine that is extremely
potent and dangerous.
• It produces an intense “high” that wears off
quickly leaving the users brain with too little
dopamine
• The user is left depressed and sad and quickly
seeks another dose of the drug.
Opiates
• Opiates are a powerful class of pain killing
drugs
• Opiates mimic natural chemicals in the brain
know as endorphins, which normally help to
overcome sensation of pain
• The first doses of these drugs produce strong
feeling of pleasure and security
• The body quickly adjust to the high levels of
endorphins and then cannot go without the
drug
• When a user tries to stop taking the drug they
suffer from uncontrollable pain and sickness
because the body cannot produce enough
natural endorphins
Marijuana
• Marijuana is the most widely abused illegal
drug
• Smoking or ingesting THC (the active
ingredient of marijuana) produces temporary
feelings of euphoria and disorientation
• Smoking marijuana is more destructive to the
lungs than smoking tobacco
• Long-term use of marijuana can result in loos
of memory; inability to concentrate; and in
males, reduced levels of testosterone
Alcohol
• Alcohol is one of the most dangerous and
abused legal drugs
• Alcohol is a depressant that slows down the
rate at which the central nervous system
functions
• It slows down reflexes, disrupts coordination,
and impairs judgment
• Women who are pregnant and drink run the
risk of having a child with fetal alcohol
syndrome
• Fetal Alcohol Syndrome (FAS) is a group of
birth defects caused by the effects of alcohol
on the fetus.
• Babies born with FAS suffer from heart
defects, malformed faces, delayed growth and
poor motor development
Alcohol and disease
• Alcoholism is a disease that is the result of a
person becoming addicted to alcohol
• Long term alcohol abuse destroys cells in the
liver, and reduces the livers ability to handle
alcohol
• The formation of scar tissue can happen, this
is known as cirrhosis of the liver
• This blocks blood flow in the liver and can lead
to liver failure.
Drug Abuse
• Drug abuse = the intentional misuse of any
drug for nonmedical purposes
• Drug abuse can lead to physical damage to
your body or produce a psychological
dependence
• These dependences can lead to addition
• Addiction = an uncontrollable dependence on
a drug
– Addiction can be either physical or psychological
• Psychological dependence is when a person
has a mental craving or need for a drug
• Physical dependence is when the body cannot
function without the drug
– Stopping the drug will result in pain, nausea, chills
and fever