Class 12 Biology Human Health Disease Drugs and alcohol abuse

Drugs and alcohol abuse

The drugs which are commonly abused are opioids, cannabinoids and coca alkaloids.


  • Opioids are the drugs which bind to specific opioid receptors present in our central nervous system and gastrointestinal tract.
  • Heroin commonly called smack is chemically diacetylmorphine which is a white, odourless, bitter crystalline compound and is obtained by acetylation of morphine extracted from the latex of poppy plant Papaversomniferum
  • Heroin is a depressant and slows down body functions.



  • Cannabinoids interact with cannabinoid receptors present principally in the brain.
  • Natural cannabinoids are obtained from the inflorescences of the plant Cannabis sativa.
  • The flower tops, leaves and the resin of cannabis plant are used in various combinations to produce marijuana, hashish, charas and ganja.
  • Effects on cardiovascular system of the body.

Fig.Cannabis sativa  

Fig. marijuana   

Coca alkaloid

  • Coca alkaloid or cocaine is obtained from coca plant Erythroxylum coca.
  • Coca alkaloid interferes with the transport of the neuro-transmitterdopamine.
  • Cocaine, commonly called as coke or crack .
  • It has a potent stimulating action oncentral nervous system, producing a sense of euphoriaand increased energy.
  • Excessive dosage of cocainecauses hallucinations.

Fig.Erythroxylum coca leaves  

  • Some plants withhallucinogenic properties are Atropabelladona and.

Fig.Atropa belladonna  

  • Drugs like barbiturates, amphetamines,benzodiazepines, lysergic acid diethyl amides (LSD) are used asmedicines to help patients cope with mental illnesseslike depression and insomnia, are often abused.
  • Morphine is a very effective sedative and painkiller is often abused.


  • Tobacco conatins nicotine, an alkaloid.
  • Nicotine stimulates adrenal gland to release adrenaline and nor-adrenaline into blood circulation, both of which raise blood pressure and increase heart rate.
  • Smoking of tobacco is associated with increased incidence of cancers of lung, urinary bladder, throat, oral cavity, bronchitis, emphysema, coronary heart disease, gastric ulcer etc.

Fig. tobacco leaves  

Share these Notes with your friends  

< Prev Next >

You can check our 5-step learning process