D5 presentation

Stimulants

Chynna & April

Stimulants

Drugs that increase a person’s mental alertness and awareness by stimulating the brain and central nervous system

They are drugs that alter the levels of neurotransmitters

They act as opposites to depressants. Examples: amphetamines, epinephrine

(adrenaline), nicotine, caffeine

D.5.1 List the physiological effects of stimulants

Physiological effects:

increase in heart rate blood pressure constriction of arteries relaxation of air passages therefore an

increase breathing rate dilation of pupils sweating reduced appetite Increase concentration

D.5.1 List the physiological effects of stimulants

Other long term side effects:

emotional instability or depression restlessness sleeplessness delusions and hallucinations

D.5.2 Compare amphetamines and epinephrine (adrenaline)

Epinephrine (adrenaline): a hormone secreted by the adrenal medulla upon stimulation by the central nervous system A response to stress Results in Anger or fear Causes: increased heart rate, blood

pressure, cardiac output, carbohydrate metabolism


Amphetamines : chemically related to adrenaline Sympathomimetic drug Initially used to treat narcolepsy and issued to

airmen in WWII to combat fatigue. 50s and 60s used as anti-depressants and slimming

pills. Regular use can lead to both tolerance and

dependence Short-term effects: increase heart race and

breathing, dilation of pupils, decrease in appetite fatigue possible depression (as it wears off)

Long term effects: weight loss, constipation, emotional instability


Physiological Similarities

Increase physical energy by: 1) Increasing heart rate and blood pressure. 2) Increasing blood flow to the brain and muscles. 3) Increasing air flow to the lungs

Increase mental awareness; trigger the "fight or flight" syndrome

Dilation of the pupils Reduce appetite induce a sense of euphoria Both can lead to the rapid development of both tolerance and

dependence (addiction), Both can have serious long-term effects if abuse/over used -

depression and reduced resistance to infection. Abuse of amphetamines through overuse is a serious problem.


Physiological Differences

epinephrine (adrenaline) is regulated/produced naturally by the brain

amphetamines are synthetic drugs Amphetamines are

sympathomimetic


Sympathomimetic drugs

Mimics the effect of stimulation on the sympathetic nervous system, which deals with subconscious nerve responses

Mimic the effects of naturally produced epinephrine (adrenaline)

speeds up heart rate increases sweat production increases breathing rate examples: nicotine, amphetamine,

methamphetamine, speed, ecstasy

Comparison of the Structures (similarities and differences)

Both based on the phenylethylamine structure Both have a benzene (aromatic) ring with a hydrocarbon

chain containing an amine. Primary amine (1 C atom attached to N atom) in

amphetamine and secondary amine (2 C atoms attached to N atom), NH in epinephrine.

Epinephrine has three hydroxy (-OH) groups while amphetamine has none.

Ethyl Amine Structure

D.5.3 Discuss the short & long term effects of nicotine consumption

Nicotine - obtained from tobacco plants, tomatoes, potatoes, eggplants, green peppers

Usually it is taken in by inhalation of smoke from cigarettes, cigars, and pipe tobacco, and chewing.

A fat soluble molecule and is easily able to go through blood-brain barrier and thus affects brain activity.

Increases the release of adrenaline effects change with time, bringing about

dependence and increased toleration.

Nicotine

Largely responsible for 1/3 of the world’s population being addicted to smoking

Withdrawal symptoms: craving for tobacco, nausea, weight gain, insomnia, irritability, and depression

Sympathomimetic drug


Short term physiological effects of nicotine:

increased heart rate / blood pressure reduced urine output as stimulating effect Increased levels of concentration/

alertness Reduced anxiety and tension Constricts blood vessels stress to heart Smoking for the first time: nausea,

vomiting, diarrhea


Long term physiological effects:

Increased risk of cancer Increased risk of heart disease/coronary thrombosis/peptic

ulcers Increased risk of stroke Withdrawal symptoms/Weight gain on quitting Physical and psychological dependences and tolerance Toxic chemicals from smoking can increase risk of mouth,

throat, and lung cancer CO from smoking reduces ability of the blood to carry CO2 Increased risk of bronchitis and emphysema Cigarettes are costly nicotine addiction increases financial

strains on families Can cause lung disease and adverse effects on pregnancy

D.5.4 Describe effects of caffeine & compare structure with that of nicotine

Caffeine: most widely used stimulant Present in coffee, tea, cola drinks, some pain killers, other

medicines Evidence that consuming 400 mg of caffeine a day or

more can cause dependence and physical side effects Caffeine is a respiratory stimulant In general, an intake of more than four cups of coffee per

day is excessive. Pregnant women are advised to limit their caffeine intake.

Included in common painkillers to speed up effects (ex. nicotine, morphine, codeine, cocaine)

Is an Alkaloid – nitrogen-containing compounds of plant origin containing heterocyclic rings and tertiary amine groups

Stimulates the nervous system by increasing the metabolic rate of nerve cells.


Caffeine Content of different products

Cup of ground coffee 80-120 mg Cup of instant coffee 65 mg Cup of tea 40 mg Cup of cola 40 mg Bar (100g) of plain chocolate 80 mg


Comparison of the structures of nicotine and caffeine

Similarities

Both contain a tertiary amine group. Both contain and five member rings made of carbon and nitrogen

atoms. Both contain a six member ring made of carbon and nitrogen

Differences

Caffeine contains two amide groups, nicotine does not. Both contain an alkene (C=C) group. Caffeine has one and nicotine

has two In caffeine the six and five member rings are fused while in nicotine

they separated. Caffeine contains two carbonyl (C=O) groups and two amide (-N-

C=O) groups

D5 presentation

Health & Medicine

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