Flashcards in 8.1.2 biological causes of drug taking Deck (16)
What is the mode of action for alcohol
alcohol makes GABA more effective by further slowing down the speed that messages are passed across synapses.
Alcohol is an agonist of GABA receptors. A glutamate antagonist (excitatory neurotransmitter ) .
Alcohol increases the amount of dopamine and serotonin.
Stimulates the reward pathway. Fight or flight reflexes slow down, noradrenaline action reduced. frontal lobe affected, inhibitory systems are less effective and more likely to take risks.
Reduces serotonin activity long-term and creates depression
What are the physical effects of taking alcohol
blood vessels dilate, become warm and flushed. GABA made more effective and speech affected, slower reaction times. Frontal lobes depressed, motor skills and coordination affected.
Dehydration caused by inhibition of ADH which leads to increased urination
What are the psychological effects of taking alcohol
Targets social areas of brain. reduces stress levels and can lead to psychological dependence. Reduces effectiveness of inhibitory mechanisms. Leads to increased confidence and relaxation but then can lead to exhibitionism and extreme behaviour
What is the tolerance of someone taking alcohol
Short-term tolerance can develop quickly.
Body produces more enzymes to break down alcohol quickly and more alcohol is needed to produce the same affect
describe Withdrawal of alcohol
6 to 12 hours after the last drink is the hangover.
Shakes, vomiting, nausea, headaches.
Heavy drinkers can experience alcohol withdrawal symptoms. Brain becomes hyper excited. Firefly actions may become overactive leading to hallucinations, confusion, anxiety and can be fatal
What is the mode of action for heroin
attaches to receptors for endorphins (Mu opioid receptors). endorphins cause the release of dopamine in the reward pathway.
Endorphins have an analgesic effect (released naturally during stress and pain situations) . heroin taken and enters the brain, is hydrolysed morphine, morphine binds to opioid receptors in the reward pathway.
This activates opioid receptors to inhibit activation of GABA, Low GABA means dopamine floods the synapse.
Sustained activation of postsynaptic membrane and pleasurable feelings experienced
What are the physical effects of heroin
Warm skin, dry mouth, heavy limbs.
Heart rate and breathing rate reduced, affects the activity of brain stem. Mental functioning impaired
What are the psychological effects of taking heroin
euphoria. Anal gestic affects. Removes aches and pains and gives calm feelings.
We’re not taking heroin, the user compares their life to no feelings of euphoria and they can become confused and anxious so want to take more heroin to reduce this
Describe tolerance of heroin
produces long-term chemical imbalances. Which are not easily reversed.
The brain activates less of its own natural production of dopamine.
In order to get the same high uses need to increase dosage.
Certain parts of the brain will only function in presence of the drug
Describe withdrawal of heroin
Agitation, muscle and bone pain, insomnia and cold flushes
Describe mode of action for nicotine
enters brain and binds to nicotinic receptors, stimulating the release of ACh.
Same molecular shape as neurotransmitter so works as an agonist stimulating the synapses.
The synapse has become flooded with ACh.
Noradrenaline levels rise and the sympathetic nervous system is stimulated. Increases transmission of dopamine , positive feelings towards smoking.
Endorphin levels rise and pleasure and relaxation felt
Describe physical effects of nicotine
highly addictive. Instantaneous effect.
Effects were off after a few minutes causing the need to smoke repeatedly.
Stimulates dopamine reward system.
Increases carbon dioxide in the blood.
Less oxygen available, grey skin, irregular heartbeat, premature skin aging and lung disorders
What are the psychological effects of nicotine
Relaxation, stimulates reward system, reduces stress
Describe the tolerance of nicotine
Brain creates more nicotinic receptors. Metabolise quickly. Tolerance lasts overnight, therefore first cigarette is the strongest.
Person smokes more frequently to avoid withdrawal symptoms
Describe withdrawal of nicotine
irritability, sleep disturbance, headaches, difficulty concentrating, increased appetite. Psychological difficulties of not having the enjoyable act of smoking