THE USE AND ABUSE OF DRUGS
DRUG = any chemical substance administered externally that modifies or affects chemical reaction in body
Medically-any subs. that helps body fight illness or disease
Drugs induced to body
i.nose-inhalation
ii.mouth-orally
iii.skin-application + sub-cutaneous injection
iv.vein-intravenous injection
v.muscles-muscular injection
vi.anus/vagina-insertion (constipation, spermicides, contraceptives)

Medicinal Drugs
-penicillin: treatment for bacterial infections (gonorrhoea + syphilis)
-aspirin: pain killer, reduces fever
-anaesthetics: to cause numbness (cocaine)

Drug abuse-taking of drugs in excess or not under doctors prescription

Herion-depressant-white, bitter: acetyl morphine from poppy plants
Administration:
-subcutaneous injection, skin popping
-intravenous injection-directly into veins (fast relief)-unsterilised needles > AIDS + Hepatitis B
-inhalation-sucking heroin powder into nose / heroin heated in Al foil, smoke inhaled (> nose cartilage break down)

Uses-strong pain killer, used for severe pain, but ppl get dependent on it
As physical dependence increases, so does psychological dependence

After taking heroin
Stage 1(Euphoria):short lived pleasantness & happiness >depressing feeling >same effect -higher dosage >addicted
causes low feeling, depression, dull senses, feeling of well-being, reduces hunger, relieves tension, constipation, memory failure, impotence, liver doesnt function properly
Stage 2(Addiction): withdrawl syptoms: anxiety, stomach upset, watery eyes, vomitting, diarrhoea, convulsions, hallucinations, shivering

Alcohol-depressant-slows down certain functions of brain
Initially psychological dependence, reduce tension, worries, stimulate appetite > physical dependence
-impares judgement (blurred vision, poor muscular coordination), reduces self-control, reduce dexterity, cirrhosis of liver (liver cells soft > hard fibrous tissue > liver doesnt function properly), peptic ulcers (increase acid secretion), kidney disease, heart disease, hypertension, atherosclerosis, pins & needles in appendages, loss of appetite, insomnia, unconsciousness (high dosages), increased anxiety, rowdy + violent behaviour, poor work attitudes, crime

withdrawal syptoms-trembling, sweating, delirium tremens (terrifying delusions due to prolonged drunkness), frightening hallucinations

Smoking
Cigarette: drug, >4000 chemicals, contains:
Nicotine-poisonous, addictive stimulant drug (> depressant), increases secretion of adrenaline > increase heart rate + high blood pressure, makes blood clot more easily
Carbon Monoxide-combines w/ haemoglobin > stable carboxyhaemoglobin, O2 carrying capacity reduced up to 15%, damages inner lining of blood vessels > atherosclerosis
Tar-brown sticky substance, accumulates in lungs during smoking, contains many (co-)carcinogens. paralyses cilia
Irritants-substances (hydrogen cyanide) paralyses cilia in air passages > more sputum, damage inner lining of blood vessels, irritate nose, eyes, throat

Cilia: cleaning mechanism of lungs, moves mucus to back of mouth to be swallowed, mucus traps dust particles + germs in air, damaged > chemicals cause more damage to lung tissues

Smoking during pregnancy-poisonous chemicals enter babys blood, nicotine narrows blood vessels in placenta, CO replace O2 supply in baby > low birth rate, low IQ, reduce birth weight, premature birth, miscarriage, still birth, deformed

IMMEDIATE EFFECTS
-increase heart rate, narrow small blood vessels, increase hormone levels, harder breathing (make up for less O2 reaching blood)

SHORT-TERM EFFECTS-constriction of bronchioles of lungs + cilia lining air passages stop beating
-nicotine, stimulant, increases nervous system's activities and relieves tension and fatigue-blood vessels > narrow, heart rate increases, blood pressure increases, urine production decreases
1st time smoker often feels dizzy and may vomit

LONG-TERM EFFECTS(may take years to develop, but severe and causes death) -Emphysema:- substances in tobacco smoke weaken alveoli walls > irritants cause smoker to cough > bursts weakened alveoli > surface area of lungs reduced, less O2 > breathlessness and exhaustion
-Bronchitis:- chemical substances in tobacco smoke > stop beating of cilia in air passages > inflammation of walls of air passages + over production of mucus > breathlessness + wheezing (consumes energy > O2 may not be sufficient available to tissues > fatigue + exhaustion)
-Lung Cancer:-Tar, nicotine + carcinogens in tobacco smoke increase chances of lung cancer. Cells in lungs divide uncontrollably > growth outgrowth (tumors). Cancer: bladder, mouth, intestines, throat may occur
-Heart Disease:-Nicotine and CO from cigarette smoke increase tendency for to clot > coronary thrombosis, CO increases rate of fatty material depositing in arteries > atherosclerosis
-nicotine increase fatty acids in bloodstream > risk of heart disease, angina, high blood pressure, coronary thrombosis-gastric + duodenal ulcers, strokes due to arterial disease in brain, tooth decay, gum disease and TB

smoking addicts may develop withdrawal symptoms if try to stop smoking (become irritable, sleepless, numbness in arms and legs, inability to concentrate and coughing more than usual)

Antibiotics
-medicinal drugs for treatment of bacterial diseases
-obtained from micro-organisms (fungi + bacteria) and works best against a certain bacteria (penicillin, tetracyclin streptomycin-TB)
-do not kill viruses > cant cure viral diseases, cold
-injected, orally, applied to skin
-less effective due to resistant stains of micro-organisms (mutation, change in DNA), an individual can developed antibiotic resistance(resistant bact. multiply rapidly: more food, O2, space, less competition, excretory products)
-antibiotics kill bact. (has protective protein coat) by dissolving bacteria cell wall > antibodies in body destroy bact.

drug dependance/addiction-need of a drug compulsory to lead a normal life, addict has to take it
physical dependance-needs drug for normal psychological functions, stops > withdrawal syptoms
psychological dependance-addict: compulsion to use drug to fuction normally and to avoid withdrawal syptoms
withdrawal syptoms-physical syptoms developed when addict stops taking drug, due to readjustment of cells to function normally w/o drug, begin 12-16h after stop taking, last up to 2 weeks, e.g. running nose, watery eyes, sensitivity of light + sound, aching muscles, chills, vomitting, goose pimples, convulsions (trembling)
drug tolerence-when a person takes a certain amount of a drug > doesnt exp. expected effect

Stimulants- stimulate CNS- emphetamines (counteract depression + hunger, prevent fatigue), cocaine
Depressants-overcome insomia + treat epilepsy- alcohol, barbiturates (sleeping pills)
Hallucinogens-person exp. hallucinations, distorted images- canabis, marijuana, LSD-lysergic acid diethylamide
Opiates-narcotic drugs- relieve pains, induce sleep- herion, opium, morphine

Diversity of Organisms
Nutrient cycles and Ecology
Parasitism
The Human Impact on the Environment
Reproduction in plants
Sexual reproduction in animals
Genetics
Cell Structure and Organisation
Enzymes
Nutrition
Transport in Plants
Support, Movement and Locomotion
Transport system in man-circulatory system
Respiration
Excretion
Homeostasis
The Eye
Nervous System
Chemical Control of Plant Growth

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