BPK 140 Chapter 13: Drugs
22 Dec 2018
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Drug: any substance taken in order to change the structure or function of the body. Prescription drugs, only available with prescription from a medical doctor. Psychoactive drugs act on the psyche, exert effect on the brain -- change in perception, mood, thinking, behaviour. Drug molecules get to the brain from the bloodstream, crossing the blood/brain barrier (network of blood vessels and tissue made of closely spaced cells. Protective physical barrier that keeps substances out of the brain, bind to specific sites on the surface of nerve cells, leading to nerve cell activity change. Injected intravenously reach brain quicker and drugs that are smoked. Drugs can be absorbed across the mucous membranes of the mouth (chewing tobacco), nose (snorting), or rectum. Injecting/smoking more likely to cause dependence; strong stimulus- response pairing, effect occurs soon after taking drug, creating association or memory. Drugs injected and smoked wear off quicker, user takes another hit to maintain high.
