Health can be defined as a state of complete physical, mental and social well-being. Health is affected by three factors-
The conditions in which one or more organs of the body are not working properly, characterized by various signs and symptoms are called diseases. The organisms which cause diseases are called pathogens.
Diseases can be broadly classified into two types-
Non- infectious diseases: Non-infectious diseases are those which are not transmitted from an infected person to another person.
Infectious diseases includes-
Infectious diseases are those which are transmitted from an infected person to another healthy person.
Typhoid
Pneumonia
Ringworm
Common cold
Malaria
Ascariasis
Filariasis or elephantiasis
Immunity is defined as the ability of the body to protect, defend and fight against invading pathogens like bacteria, virus, and other foreign bodies and toxic substances. There are two types of immunity.
Innate immunity: Non specific defence type of immunity present at the time of birth achieved by the provision of 4 barrier types – the physical barrier, physiological barrier, cellular barriers, cytokine barrier
Acquired immunity: Pathogen specific immunity that is characterized by memory.
Active and Passive Immunity: Active immunity is where the host produces antibodies in the form of dead or living microbes when it is exposed to antigens. It is a slow process, taking time to provide its full effective response. Passive immunity, on the other hand, is the immunity where ready-made antibodies are given directly to protect the body against any foreign agents.
Vaccination: The act of introducing a vaccine into the body to produce immunity to a specific disease.
Immunization: A process by which a person becomes protected against a disease through vaccination.
The exaggerated response of the immune system to certain antigens present in the environment is called allergy. The substances to which immune response is produced are called allergens. Common examples of allergens are mites in dust, pollens, animal dander etc. Allergy is due to the release of chemicals like histamine and serotonin from the mast cells.
The antibodies produced to these are of IgE type. Symptoms of allergic reactions include sneezing, watery eyes, running nose and difficulty in breathing. The patient is diagnosed by injecting or exposing the patient to very small doses of allergens. Drugs like anti-histamine, adrenalin and steroids quickly reduce the symptoms of allergy.
The immune system of body can is able to identify and differentiate between self and non self. Due to genetic and other unknown reasons, the body attacks self-cell which results in damage to the body and is called auto-immune disease. Rheumatoid arthritis is an auto-immune disease.
Immune system consists of-
Lymphoid organs: The organs where origin and/or maturation and proliferation of lymphocytes occur are called lymphoid organs. Lymphoid organs are of two types- Primary lymphoid organs and Secondary lymphoid organs.
Lymphoid tissue: Lymphoid tissue are located within the lining of the respiratory, digestive and urogenital tracts. Lymphoid tissues are also called mucosalassociated lymphoid tissue (MALT) which constitutes about 50 per cent ofthe lymphoid tissue in human body.
B- cells and T-cells: T cells (thymus cells) and B cells (bone marrow- or bursa-derived cells) are the major cellular components of the adaptive immune response. T cells are involved in cell-mediated immunity, whereas B cells are primarily responsible for humoral immunity (relating to antibodies).
Antibodies: Antibodies are Y-shaped proteins that bind to the body's foreign invaders and signal the immune system to get to work. Antibodies are specialized, Y-shaped proteins that bind like a lock-and-key to the body's foreign invaders — whether they are viruses, bacteria, fungi or parasites.
The word AIDS stands for Acquired Immuno Deficiency Syndrome. This means deficiency of immune system, acquired during the lifetime of an individual indicating that it is not a congenital disease.
Acquired Immuno Deficiency Syndrome is caused by HIV(Human Immunodeficiency Virus) a member of the retrovirus group.
It is generally transmitted through sexual contact with infected person, blood transfusion with contaminated blood and its products, through the share of infected needles, from the infected mother to her child through the placenta. ELISA (Enzyme-linked immunosorbent assay) is the diagnostic test for AIDS
Cancer is the uncontrolled cell division leading to the formation of a mass of cells called as a tumor. Contact inhibition is the property of normal cells by virtue of which contact with other cells inhibits their uncontrolled growth. Cancer cells lost the property of contact inhibition and as a result of this, cancerous cells continue to divide giving rise to masses of cells called tumors.
Tumors are of two types: benign and malignant.
Causes of cancer:
The drugs which are commonly abused are opioids, cannabinoids and coca alkaloids.
Opoids: 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: 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.
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.
Tobacco: 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.
Adolescence means both ‘a period’ and ‘a process’ during which a child becomes mature in terms of his/her attitudes and beliefs for effective participation in society. 12-18 years of age may be thought of as adolescence period. Adolescence is accompanied by several biological and behavioural changes. Curiosity, need for adventure and excitement, and experimentation, constitute common causes, which motivate youngsters towards drug and alcohol use.
Addiction is a psychological attachment to certain effects –such as euphoria and a temporary feeling of well-being – associated with drugs and alcohol. With repeated use of drugs, the tolerance level of the receptors present in our body increases and consequently the receptors respond only to higher doses of drugs or alcohol leading to greater intake and addiction. Dependence is the tendency of the body to manifest a characteristic and unpleasant withdrawal syndrome if regular dose of drugs/alcohol is abruptly discontinued. Withdrawal syndrome is characterised by anxiety, shakiness, nausea and sweating.
Excessive doses of drugs may lead to coma and death due to respiratory failure, heart failure or cerebral hemorrhage. Those who take drugs intravenously can get infected with AIDS, hepatitis B. The chronic use of drugs and alcohol damages nervous system and cause liver cirrhosis.
The use of drugs and alcohol during pregnancy is also known to adversely affect the foetus. Use of anabolic steroids in females can cause masculinisation, increased aggressiveness, mood swings, depression, abnormal menstrual cycles, excessive hair, growth on the face and body, enlargement of clitoris, deepening of voice.
In males anabolic steroids can cause acne, increased aggressiveness, mood swings, depression, reduction of size of the testicles, decreased sperm production, potential for kidney and liver dysfunction, breast enlargement, premature baldness, enlargement of the prostate gland.
The measures useful for prevention and control of alcohol and drugs abuse among adolescents-