The Effects of Drugs on the human body/ mind Flashcards
The organization of the Nervous system
Two major divisions of the nervous system
Central nervous system (CNS)
Consists of the brain and spinal cord
Integrates incoming information and coordinates all voluntary and involuntary nervous functions
* Peripheral nervous system (PNS)
Consists of ganglia and the nerves that branch from the CNS
Keeps the CNS in contact with the rest of the body
What is a neuron
Fundamental unit of the nervous system
* responsible for receiving sensory input from the external world
* sending motor commands to our muscles
* transforming and relaying the electrical signals at every step in between
How neurons communicate
Communicate with each other via electrical events called ‘action potentials’ and chemical neurotransmitters
At the junction between two neurons (synapse or synaptic cleft), an action potential causes neuron A to release a chemical neurotransmitter.
The neurotransmitter can either help (excite) or hinder (inhibit) neuron B from firing its own action potential.
Drugs/substances that affects how the brain works and causes changes in mood, awareness, thoughts, feelings, or behavior
Ways in which psychoactive drugs alter communication between neurons
* Stimulate release of neurotransmitter
* Inhibit release of neurotransmitter
* Prolong effects of the neurotransmitter
Psychoactive drugs
Psychoactive drugs and communication neurons - Tolerance
Tolerance:
Defining tolerance (it occurs when 2 biological things happens):
Pharmacokinetic tolerance (drug is not reaching the brain receptors)
Pharmacodynamic tolerance: receptors are damaged or lost.
* Occurs when higher and higher doses of a drug are
needed to generate a response
* Develops because the body steps up production of enzymes that break down the drug
Cross-tolerance
Defining Depeendence (when the body changes to adapt to the constant access and use of the drug
Psychoactive drugs and communication between neurons Addictions
Definitions: Defining Addiction: Addiction is behaviour. Substance abuse will continue despite negative consequences
Occurs when tolerance to one drug results in a lessened response to another, usually similar, drug
Occurs when someone can no longer function normally without the drug
The drug is needed for physical or psychological well- being
Certain drugs stimulate the “pleasure centers” in the brain and encourage continued use
Different than tolerance, dependence
“Behaviour”
Certain drugs stimulate the “pleasure centers” in the brain and encourage continued use
Examples of Drugs
Alcohol
Marijuana Stimulants
* Cocaine
* Amphetamines
* Nicotine
Hallucinogens
Opiates
* Prescription painkillers
* Heroin
Examples of Drugs
Alcohol
Marijuana Stimulants
* Cocaine
* Amphetamines
* Nicotine
Hallucinogens
Opiates
* Prescription painkillers
* Heroin
Alcohol
The effects of this on a person’s behavior depend on the blood alcohol level
* Grams of alcohol per 100 ml of blood
* Example: 1 g alcohol/100 ml blood = blood alcohol level of 1%
The blood alcohol level is affected by
* How much alcohol is consumed
* How quickly it is consumed
* The rates of absorption, distribution, and metabolism of the consumed alcohol
Absorption and distribution
* The intoxicating effects of alcohol begin when it is absorbed from the digestive system into the blood and reaches the brain
* 20% of alcohol is absorbed at the stomach
The effects of alcohol are felt in about 15 minutes Food in the stomach slows alcohol absorption
Effects of alcohol on the body
- Nervous system
- Alcohol is a depressant and slows neurons’ activity
- Areas of the brain are affected in sequence
Higher cortical (“thinking”) centers
Balance and coordination centers
Regions responsible for consciousness - Excessive amounts of alcohol can cause unconsciousness, coma, and death from respiratory failure
Factors affecting intoxication
Food, Strength of Drink, Mood, Rate of consumption, Medications
MARIJUANA CANNABIS SATIVA
- Principal psychoactive ingredient in the leaves, flowers, and stems is delta-9-
tetrahydrocannabinol (THC)
Binds to receptors in brain regions involved in thinking, memory, and motor control
May regulate mood, memory, pain, appetite, and movement
Is smoked, vaporized, consumed in food or drink, other
Health-related effects of long-term use:
* Respiratory system
Experiences the most harmful effects
Caused by residual material in the smoke; not caused by THC
* Carbon monoxide prevents red blood cells from carrying oxygen
Circulatory system
* Causes an increase in heart rate and blood pressure
Reproductive systems
* THC is structurally similar to estrogen
* Males: THC reduces levels of testosterone and sperm production
* Females: effects unclear
* A LOT OF PEOPLE USE THIS FOR PAIN MENTAL HEALTH PROBLEMS AND TROUBLE SLEEPING
- Extracted from leaves of the coca plant
- Methods of intake
Inhalation into nasal cavity (powder)
Smoking (freebase and crack) - Interferes with the reuptake of dopamine
Causes a rush of intense pleasure, a sense of self-confidence and power - Increases the effects of norepinephrine
Prepares the body systems for emergency
Cocaine (stimulant)
AMPHETAMINES (stimulants)
- Synthetically produced; closely resemble dopamine and norepinephrine
- Example: methamphetamine (“crystal meth”)
- Effects
Cause user to feel exhilarated and confident
Suppress appetite and need for sleep
Last longer than those produced by cocaine - Tolerance to amphetamines develops along with both physical and psychological dependence
- Psychoactive ingredient in tobacco products
- Highly addictive
- Activates acetylcholine receptors
facilitates release of dopamine and serotonin, which creates pleasurable feelings of relaxation - CVD risk: Increases heart rate and stickiness of platelets, constricts blood vessels
Nicotine (stimulants)
