PHAR 100 - Module 2 Flashcards
functions of the nervous system
- recognize
- process and integrate
- react
CNS
- brain → receives and processes info
- the spinal cord - carries sensory info
forebrain
- cerebral cortex (cerebrum) → sensory and motor coordination, intelligence, memory, vision, speech
- thalamus → relay centre from which impulses are transmitted to the cerebral cortex; coordinates and filters incoming signals
- hypothalamus → controls involuntary functions, feeding, sexual responses
- limbic system → integrates memory, emotion and reward
- pituitary → secretes hormones
midbrain
relay centre for visual (eye) and auditory (ear) stimuli or signals
the hindbrain
- pons → conducting signals from the cerebral cortex down to the medulla and cerebellum
- medulla → regulation of respiration, HR, BP
- cerebellum → coordination and posture
neuron
- cell body → contains the nucleus
- dendrites → receive incoming info
- axon → carries incoming info away from dendrites and cell body
glutamate
primary excitatory neurotransmitter in the CNS
gamma-aminobutyric acid (GABA)
primary inhibitory neurotransmitter in the CNS
acetylcholine
produces an excitatory response in the CNS
types of cholinergic receptors
- nicotinic receptors → can be stimulated by acetylcholine/nicotine
- muscarinic receptors → can be stimulated by acetylcholine/muscarine
dopamine
a catecholamine
norepinephrine
can bind to a large number of receptor types, but the 2 main classes are alpha and beta
serotonin
hyperactivity of the serotonergic system is involved in anxiety, and hypo-activity has been implicated in depression
opioid peptides
3 main classes of opioid peptides: enkephalins, endorphins and dynorphins
substance use disorder
when a person’s use of a drug or other substance leads to health issues of problems at work, school or home
factors influencing substance use disorder
- genetic factors
- co-existing disorders
- environmental risk factors
- developmental aspect
the dopamine hypothesis
explains addiction; suggests that drugs of abuse increase dopamine in the reward systems of the brain
characteristics of addictive drugs
- increase dopamine (CNS stimulants, alcohol, cannabis)
- produce novelty (LSD, ecstasy)
- reduce anxiety (benzodiazepines, barbiturates)
substance abuse
a pattern of substance use manifested by recurrent and significant adverse consequences
abuse potential of a drug
- dependence liability → nature of the drug; route of administration; amount and frequency of use
- availability
- inherent harmfulness
dependence liability
- tendency of a drug to cause dependence and addiction
- determined by 3 factors:
→ nature of the drug - most drugs are natural reinforcers (like food)
→ route of administration - drugs that can be administered by routes that give rapid absorption and hence rapid effects have a greater potential for abuse
→ amount and frequency of use - the greater the dose and the frequency of use, the greater the potential for dependence
inherent harmfulness
- potential of the drug to cause harm
substance dependence
a complex disease process of the CNS that regulates repeated consumption, or chronic use, of the substance
drug tolerance
- repeated administration of a given dose of a drug has progressively less pharmacological effects, or a state in which the dose of a drug must be increased to obtain the same magnitude of pharmacological effect as was produced by the original drug dose
- usually expressed by a shortened duration of action and a decreased magnitude of effect
drug dependence and withdrawl
- an abnormal physiological state produced by repeated administration of a drug that leads to the appearance of a withdrawal syndrome when drug administration is discontinued or dose is decreased
drug addiction
a state in which stopping or abruptly reducing the dose of a given drug produces non-physiological symptoms
substance abuse example
Becky binge drinks once a month so she blacks out
substance dependence example
Amanda has been drinking 4 black coffees since starting undergrad; if she doesn’t drink it she gets headaches and is irritable
amphetamines chemistry
- synthetic organic compounds
- structurally similar to dopamine and norepinephrine
amphetamines pharmacology
- increase excitation by increasing amount of dopamine or norepinephrine in the synaptic cleft
- amphetamines are substrates for the dopamine transporter → compete with dopamine for the dopamine transporter
- once in the nerve they block the VMAT (transporter that brings dopamine into vesicles to be released)
- increase in dopamine in the synaptic cleft = increase in CNS excitation
amphetamines CNS effects
- decreased threshold for transmitting sensory input to the cerebral cortex, leading to excitation
- feeling of euphoria and reward
- temp-regulation and feeding centre modifications, leading to appetite suppression
- increase in aggressive behaviour and mood swings
amphetamines effects of short-term use
- heart attack, heart pain
- cardiovascular collapse
- increased respiratory rate
amphetamines effects of long-term use
- chronic sleeping problems
- poor appetite
- anxiety
- elevated BP
amphetamines therapeutic uses
- narcolepsy → a chronic sleep disorder
- ADHD → drug increases attention/concentration
amphetamines abuse potential
- abuse liability of amphetamines is very high (euphoria)
- produce a rapid and intense response
- inherent harmfulness is due to its long-term toxicities
amphetamines dependence
- tolerance → develops to euphoria and mood-elevating effects
- dependence → cessation results in mood depression, prolonged sleep, huge appetite
- addiction → euphoria and “rush” will act as rewards
cocaine pharmacology
- causes generalized CNS stimulation
- inhibits the active re-uptake of dopamine and serotonin into the presynaptic nerve terminal
- increases the concentration of these transmitters in the synaptic cleft, and in turn increases activation of the post-synaptic receptors
cocaine effects in the CNS
- almost indistinguishable from amphetamine in it’s acute effects and pattern of toxicity
- main difference is that cocaine has a shorter duration of action
cocaine therapeutic uses
- local anesthetic for the mouth and throat
cocaine effects of long-term use
- toxic psychosis
- hallucinations
- permanent brain damage
cocaine abuse potential
- has one of the highest abuse liabilities
cocaine dependence
- tolerance → develops to the mood-elevating effect, but not the psychotic effect
- dependence → withdrawal symptoms are similar to those from amphetamines
- addiction → can occur
nicotine pharmacology
- nicotine exists in cigarette smoke in small particles, and when inhaled these particles are rapidly absorbed
- stimulates nicotinic receptors at synapses
- activation of nicotinic receptors increases psychomotor activity, attention
nicotine therapeutic uses
only therapeutic use is in smoking cessation programs
nicotine short-term effects of smoking
- dizziness, nausea, headache
- mild euphoria, increased ability to concentrate
nicotine long-term effects of smoking
- respiratory and carcinogenic effects
- lung disease risk is increased
nicotine abuse potential
- is a powerful reinforcer and has a high degree of abuse liability
nicotine dependence
- tolerance → doesn’t really occur
- dependence → withdrawal from smoking results in irritability, restlessness, anxiety, insomnia
caffeine pharmacology
- in the brain, activation of receptors termed adenosine receptors stimulates GABAergic neurons that then inhibit dopamine release
- actions of caffeine are exerted by competitively blocking adenosine receptors in the brain
- when caffeine blocks these receptors, the neurons are released from the adenosine inhibition, causing an increase in dopamine release
short-term effects of caffeine
- mild mood-elevation, reduce fatigue
- constriction of cerebral blood vessels, rapid HR
long-term effects of caffeine
restlessness, nervousness, insomnia, increased urinary output
caffeine abuse potential
- abuse liability of caffeine is low
- it does act as a mild reinforcer
- inherent harmfulness is low
caffeine dependence
- tolerance → can develop
- dependence → abrupt cessation = headache, fatigue
- addiction → mild addiction can occur
amphetamines in sport
- CNS stimulants that work by increasing the release of the neurotransmitters dopamine and norepinephrine
- increased alertness, feeling of power, reduction of fatigue, increased aggression
anabolic steroids in sport
- increase muscle mass
- produce an anti-catabolic response
- anabolic effects of the drug result in protein production
- produce aggressive behaviours
- usually has greater effects on females
benzodiazepines in sport
- drugs like Valium are used to reduce anxiety during competition
- taken by ski jumpers to calm nerves
growth hormone in sport
- HGH will increase muscle mass and strength
- not as easily detected
blood doping and erythrotopien in sport
- both techniques result in an increase in the number of red blood cells, and hence increases oxygen carrying capacity of the blood
diaretics in sport
- drugs that enhance the excretion of salt and water through kidneys
- used to reduce body water to allow the athlete to compete at a lower weight class
