Chapter 13 - Nicotine and Caffeine Flashcards
Source and purpose of nicotine in plants
Alkaloid found in tobacco leaves, made by plants to discourage insects from eating them
ways of administering nicotine
tobacco cigarettes, e-cigs, pipe, hookah, cigars
tobacco cigarette vs ENDS
Cigarettes - contain 6 to 11mg nicotine, 1 to 3 mg reaches bloodstream, enters the lungs on tiny particles called tar
ENDS - Electronic nicotine delivery systems, the device heats and vaporizes a solution of nicotine, producing an aerosol that is
inhaled (vaporization)
Nicotine Metabolism
half-life is about 2 hours, rapidly absorbed through lungs, reaches brain within 7 sec
What type of receptors does nicotine bind to? Where are some of the locations of these?
nAChRs, neuronal receptors throughout the PNS and CNS, some located presynaptically
What happens when nicotine binds to an nACHR?
They are ionotropic receptors and conduct Na+ and Ca2+ ions across the cell membrane causing depolarization and a fast excitatory response.
How does nicotine affect the reward pathway?
activating nAChRs on dopamine (DA) neurons of the mesolimbic pathway.
Physiological side effects of nicotine administration?
can activate both sympathetic and parasympathetic, Tachycardia and elevated blood pressure can increase risk of cardiovascular disease.
Release of NE and EPI from adrenal glands contributes to arousing effects of nicotine
Reduces appetite and increases metabolic rate, resulting in weight
loss; also affects GI tract.
symptoms of nicotine toxicity
nausea, dizziness, sweating, headache, palpitations, stomach ache, and clammy hands
An extremely high overdose may end with convulsions and fatal
respiratory failure due to depolarization block of the respiratory
muscles
Why do smokers tend to smoke every few hours (or more) and why is this due to reducing withdrawal effects?
In smokers, nicotine produces a calm or relaxed state, partly as relief from nicotine withdrawal symptoms. having a smoking habit increases overall stress, which is countered by continued smoking.
Nicotine administration to nonsmokers tends to elicit heightened
tension or arousal, along with lightheadedness, dizziness, and even nausea.
Treatment for tobacco dependence
self-help, cessation advice, counseling, medications, nicotine replacement therapy (NRT), non-nicotine drugs,
Caffeine sources
coffee, tea, cocoa beans, kola nuts, yerba mate, guarana berries
How do low and high levels of caffeine affect lab animals?
caffeine has biphasic effects – a stimulant at low
doses, effect is reversed at high doses
Various models argue that smoking provides certain advantages to the smoker. Which is not an example of such proposed advantage?
Smoking allows the smoker a time of increased energy and activity.
What are the effects of caffeine?
increased concentration, reduced fatigue, stimulate arousal, enhances muscle strength and power, can also cause tension, jitters, and anxiety
