Immunity and Health Aids
Till the mid-18th century, the world was under the grip of small pox which is a fatal disease.Later Dr. Edward Jenner discovered a cure against it, when he observed that milkmaids who once developed cowpox became immune to fatal form of small pox. He is well known around the world for his innovative contribution to immunization and the ultimate eradication of smallpox.
Immunity isthe ability of an organism to resist a particular infection or toxin (antigens) by the action of specific antibodies or sensitized white blood cells. It is of two types:innate immunity and acquired immunity.Innate immunity is the immunity which possessesa natural defense by the virtue of genetic constitutional make-upwhile the acquired immunity is the resistance to specific disease causing agent, which is acquired during the life-time of an organism.
Innate immunity is of two types, specific and non-specific and acquired immunity is also of two types i.e. active and passive.
Body’s natural defense includes sweat and sebum from skin, tears from eyes, hairs in nostrils, saliva in mouth, tonsils and cough in throat, acid in stomach and WBCs in blood and lymph.
Body can also be protected against diseases by immunising agents such as vaccines and sera immunising agents. Vaccine can be administered either orally or injected directly into veins or muscles. On the basis of their constituents, vaccines can be of three types that are live, killed or dead microbe and toxoid. e.g. TAB, Tetanus, BCG, DPT etc.
Serum is the fluid that remains after blood has clotted and cells have been removed.Anti-serum is obtained by injecting an animal (horse, rabbit, goat) with an antigen (snake venom, tetanus, botulism or diphtheria toxin) in sufficient amounts to trigger the production of antibodies by its blood.
The two types of immunization are active and passive immunization. Active immunisation involves the use of vaccines while passive immunisation involves the use of serum. Health aids can be used to avoid or neutralise the diseases. They include antiseptics, disinfectants, antibiotics and vaccines.
For prevention and control of many infectious diseases,Marks:1
maintenance of personal and public hygiene is very important.
Explanation:Personal hygiene means keeping the body clean, consumption of clean drinking water and food, etc. Public hygiene is taking care of proper disposal of waste and excreta, timely cleaning of water reservoirs and maintaining standard practices of hygiene in public catering.
Streptococcus pneumoniae is aMarks:1
Explanation:Streptococcus pneumoniae is a bacteria-spreading pneumonia in humans.
B-cells are stimulated to produce antibodies byMarks:1
Explanation:B-cells are stimulated by helper T-cells to produce antibodies, lack of B-cells or T-cells or both may cause SCID (severe combined immunodeficiency).
Cells involved in immune mechanism areMarks:1
Explanation:Lymphocytes are the part of specific defence system called immune system.
Which statement best describes what will most likely happen when an individual receives a vaccination containing a weakened pathogen?Marks:1
The ability to fight against infections will increase due to antibody production.
Vaccination includes the insertion a dose of weakened pathogens or its antigens to individual’s body. The presence of antigens triggers lymphocytes to make antibodies that inactivate the foreign organisms, but are specific to each one as well. Vaccination reduces the spread of disease and develops immunity.