Question

How does a body react to allergens shown by different organs?

Answer 1

1. Allergens are foreign substances, usually harmless, and are capable of initiating allergic responses in susceptible people. Common allergens are dust mites, pollen grains, animal dander, etc.
2. When allergens enter the body, they induce the production of IgE antibodies from the B cells.
3. Allergic reactions are mainly caused due to the circulating IgE antibodies which stimulate the release of chemicals like histamine and serotonin from the mast cells.
4. During allergic reactions, large quantities of IgE antibodies are found in the blood of the susceptible person. So option a and b are true.
5. Allergic responses cause the peripheral blood vessels to undergo vasodilation and the capillaries become highly permeable to allow the leaking out of large amounts of fluids from the blood into the tissues. So option c is true.
6. An increase in quantities/numbers of circulating pathogens in the blood is indicative of pathogenic infection, rather than an allergy.