Test 4 - Final Flashcards
Psychoactive Drug
- Natural or synthetic molecules that alter communication between neurons:
- Releases NTs
- /Stimulates/Inhibits NTs
- Delay Nt removal/breakdown
- Acts like a NT by binding to NT
- stimulate receptors on postsynaptic neurons
- Prevent NT action
- block receptors (prevent NT action)
Physical response to chronic use: Tolerance
- Def: progressive decrease in effectiveness of a drug
- Require more drug… longer/more frequent doses to produce the same effect
- Body tries to maintain homeostasis in the face of drugs
- Increases enzymatic production to more quickly breakdown the drug
- Decreases number of receptors on postsynaptic neurons
Dependency
- Physical changes to nervous system
- Drug is required by user for their physical or physiological well-being
- No longer able to produce “appropriate” or “normal” responses because of physical changes (in nervous system)
- Drug required to maintain level of “homeostasis”
- Withdrawal symptoms occur when drug use stop signs
Drugs that most quickly lead to dependency?
-They stimulate “pleasure” centers of the brain
- Main examples:
- Cocaine
- Amphetamines
- Morphine/Opiates
- Nicotine
Cocaine
- Increases residence time in synaptic gap of NT’s
- Dopamine - blocking reuptake
- associated with pleasure centers of the brain - Norepinephrine - simulates (or stimulates?) release
- normally involved in fight-or-flight response - Results in feeling of confidence, alertness, pleasure, and power
- Snorted, smoked, or injected
Positive effects of cocaine are short-lived and then?
- Lasts no more than 90 minutes
- Followed by a “crash”… feeling anxiety, depression, fatigue (opposite of what you feel while on it)
- Produces a “craving” for more cocaine
Cocaine Health Issues?
- Cardiovascular
- Increases heart rate, blood pressure, and interferes with nerves that regulate heartbeat
- Constricts arteries - increases blood pressure
- Regulation of heart – can result in heart attack or stroke
- Respiration
- Interferes with neurons controlling respiration
- As cocaine wears off, activity in respiration centers of brain become depressed – potentially causing respiratory failure
- Damaged nerves, membranes, blood vessels of the nose (repeated snorting)
Amphetamines
- Synthetic stimulants that interferes with reuptake and increases release of dopamine and norepinephrine
- Effects dopamine and norepinephrine
- Effects of can last for hours
- In low, controlled doses, prescription versions of these drugs increases alertness, concentration, reduced fatigue
Meth
- Street form of amphetamine
- Smoked (most common), ingested as pills, crushed then snorted, or injected
- Behavioral modification
- Prolonged use appears to have long-term negative consequences to nervous system
- Chronic meth users often suffer from impairments to memory and emotional centers of brain
- Induces euphoria, feelings of high self-esteem, increased libido, insomnia, mania
- Long-term and high doses: anxiety, paranoia, movement disorders, also hallucinations, and psychotic behavior
- (Plug reuptake pumps)
Hallucinogenic Drug?
- Ecstasy
- A diverse array of drugs – similar effects (like mushrooms, LSD, etc.)
- Visual, auditory, or other hallucinations
- Ecstasy (MDMA) or for all hallucinogenic drugs Effects:
- Serotonin (sense of well-being)
- Acetylcholine promotes release of serotonin and dopamine
- Norepinephrine
Ecstasy Physiological Effects?
- Stimulant
- Causes HYPERthermia (increased body temp - heat stroke)
- Dehydration
- If water intake is increased substantially, sodium and potassium can become diluted. Sodium needed for action potential in neuron. Better to drink something with electrolytes (gatorade)
- Ecstasy pills/liquids often contain other drugs
- Effect is more meth-like
Ecstasy Long-Term Effects
- Degradation of dopamine/serotonin releasing neurons
- Chronic…?
Opioids
- Affects opioid receptors
- Produce “morphine-like” effects – pain relief
- Variety of drugs: morphine, codeine, oxycodone, hydrocodone, tramadol, and heroin
- Easily leads to addiction, physical dependence, thus withdrawal
- Respiratory distress (death)
-Fentanyl and carfentanil – extremely potent, thus dangerous
Alcohol
- Depresses (slows down) neuron activity in the brain (of ALL)
- Tends to depress inhibitory neurons quickest
- Excitatory neurons run amuck AT FIRST (because they don’t have breaks on them)
- Release from inhibitory controls tends to reduce anxiety and creates a sense of wellbeing
Ethanol
- (Alcohol)
- The alcohol in every “alcoholic” drink – very small molecule
- Both water and lipid soluble (will enter cell very quickly; readily gets into cells)
- Standard “drink” = 0.5 oz of ethanol(/alcohol?)
- Intoxicating effects begins quickly as it is absorbed
- Absorption begins in the stomach (20%)
- Higher concentration = faster absorption (stronger the alcohol, faster you’ll get drunk)
- Food slows down absorption
Once a neurotransmitter is released into cleft, how do you stop it from working?
- Reuptake
- Enzymes
Alcohol Elimination
- Metabolized liver breaks down alcohol
- Enzymatic breakdown begins in the stomach
- About 1 standard drink per hour
- Alcohol dehydrogenase (enzymes)
- more in men than in women
- genetic patterns – more in certain populations
-small amount (5%) of alcohol excreted in urine and by lungs (breathalyzers)
Alcohol Health Issues: Heart and Blood Vessels
-Moderate use (1 drink/day) appears to help heart (decreases cardiovascular disease)
- High consumption…
- Liver disease
- Alcohol is metabolized before fat
- Fat accumulation in liver cells
- Liver cells swell and burst
- Scar tissue formation… (cirrhosis)
- Cardiovascular damage
- Nervous system problems (“wet brain”?)
- Fetal alcohol syndrome
- moves across placenta
- birth defects (are common)
- Liver disease
Alcohol Health Issues: Nervous System – Short-Term
- Depresses activity of all neurons
- neurons in higher thinking centers affected first (e.g., inhibitory neurons, motor control)
- At high levels, inhibits neurons for consciousness and breathing
- As alcohol level increases, inhibition of neurons associated with consciousness
What factors influence your drinking state?
- Size
- Weight
- Sex
- Genes
Blood – Specialized Connective Tissue (review)
- cells and platelets, soluble protein, suspended in plasma?
- functions: transportation of oxygen nutrients (glucose ions, etc.) ad wastes (CO2, etc)
- regulation of body temperature and buffers pH
- protections of immune walls
Blood Composition
- Plasma
- White blood cells
- Red blood cells
- LOOK IN CIRCULATORY PACKET
Red Blood Cells
-”Erythrocytes”
- Abundant
- drop of blood contains several millions of RBC
-Transport oxygen from lungs to cells
Red Blood Cell Structure
- Biconcave disc
- maximizes surface area/volume ratio
- flexible: easy movement
- No nuclei, few organelles
- mostly sac of the protein hemoglobin