any sbustances taken nto body that modifies or affects chemicals reactions in the body.
medicinal drugs医疗药物
Antibiotics抗生素
antibiotics are substances which kill bateria,but do not harm pther living cells.
most are fungi
penicillin青霉素
penicillin kills bacteria by stopping them making their cell walls
viruses(do not have cell walls)
bacteria
misuse of drugs滥用药物
Heroin
Heroin isa powerful depressant.This means that it slows down many functions of the brain. It reduces pain,and slow down breathing.It also slows down the function of the hypothalamus.
made of opium鸦片
it can be addictive
An addictive drug is one which cause a person to become dependent.
more tolerant耐性 of the drug
take more and more
take it by injecting注射 into their veins.
needles针头 not sterile消毒
pathogens
hepatitis virus肝炎病毒
HIV
morphine
fit into some endorphin内啡肽 receptor
reduce natural endorphins
Endorphins help to reduce sensations of pain, affect mood and reduce sensation of hunger and thrist.One situation in which endorphins are produced is when we do exercise.
affect the brain's production of their important neurotransmitter神经递质
stop use heroin
extremely unpleasant极其难受
Alcohol
broke down by the liver
take a long time
*Alocohol lengthens reaction long time
Alcohol is a depressant,which means that even small amounts of alcohol slow down the action of pats of the brain, so alcohol lengthen the time you take to respond to a stimulus
*Alcohol can increase aggression攻击性 in some people
release inhabition天性
be violent or commit
*large intakes of alcohol can kill
Large intakes of alcohol can result in unconsciousness,coma and even death.Sometimes,death is caused by a person vomiting whe unconscious,and then suffocating because their airways are blocked by vomit
Alcohol is poison
Alcoholism
alcoholic
alcoolics
damage liver
liver break down alcohol
alcohol is poisonous
cirrhosis肝硬化
One form of liver disease resulting from alcohol damage is cirrhosis,where fibres grows in the liver.This can be fatal.致命的
damage brain
loss of memory and confusion.
One way in which the damage is done is that alcohol in the body fluids draws water out of cells by osmosis.When this happens to brain cells, they shrink, and may be irreversibly damaged.
dilute urine to be produced
low levels of water in the blood
Anabolic steroids(hormone)合成代谢类固醇
steroid horomone类固醇荷尔蒙
reproductive hormones 生殖荷尔蒙
testosterone睾酮
oestrogen雌激素
progesterone孕酮
anabolic reaction合成反应
Many steriod hormones stimulate metabolic reactions in body cells that build up large molecules from small ones.
eg：One type of reaction that is stimulated by anabolic steroids is the synthesis of protein from animo acid.Testosterone,for example,cause more proteins to be made in muscles, so that muscles become larger and stronger.
Athletes and others have taken anabolic steriods to increase their musle size and strength.
dangerous
decrease the ability of the immune system to destory pathogens
