Definitions [6]
Definition: Drug abuse
Drug abuse is the improper or excessive use of drugs that leads to harmful effects on physical, mental and social health.
Definition: Cancer
Cancer is a disease characterised by uncontrolled and abnormal division of body cells due to loss of normal growth regulation.
Definition: Metastasis
Metastasis is the process by which cancer cells spread from the primary site to distant organs through blood or lymph.
Definition: Tumour
Tumour is a mass of abnormally proliferating cells formed due to uncontrolled cell division.
Definition: Malignant tumour
Malignant tumour is a cancerous tumour that grows rapidly, invades surrounding tissues and spreads to distant organs.
Definition: Benign tumour
Benign tumour is a non-cancerous tumour that remains confined to its original site and does not spread to other parts of the body.
Key Points
Key Points: Drug Abuse
- Opioids: Source - Papaver somniferum (poppy). Effect - depressant, pain killer. Example - Heroin (diacetyl morphine).
- Cannabinoids: Source - Cannabis sativa (hemp). Effect - daydreaming affects the cardiovascular system. Examples - Marijuana, hashish, charas, ganja.
- Cocaine: Source - Erythroxylum coca. Effect - stimulates the CNS, causes euphoria, irritability, paranoia. Example - Cocaine.
- Hallucinogens: Source - Atropa belladonna, Datura. Effect - unreal perceptions of unreal objects. Examples - LSD, cannabis.
- General Effect: All abused drugs cause addiction, dependence, and impair physical, physiological, and psychological functions.
Key Points: Cancer
- Meaning: Cancer is the abnormal, uncontrolled division of cells forming a mass called a neoplasm/tumour. Cancer cells lack contact inhibition and compete with normal cells for nutrients.
- Benign Tumour: Grows slowly, stays restricted to its site of origin (localised), and does not spread. It can still be harmful (e.g., brain tumour). Examples — Adenoma, Fibroid.
- Malignant Tumour: Grows rapidly, invades surrounding tissues, and spreads to other organs via blood or lymph, forming secondary tumours. This spreading process is called metastasis.
- Types of Cancer: Based on tissue affected — Carcinoma, Sarcoma, Lymphoma, Leukaemia, and Adenocarcinoma.
- Causes: Chemicals (e.g., nicotine), radiation (X-rays, gamma rays), viruses (oncogenic), oncogenes, and addictive substances (e.g., tobacco).
- Diagnosis & Treatment: Diagnosed by biopsy. Treated by radiation therapy (X-rays/gamma rays), chemotherapy, immunotherapy, and surgery.
