Question

Tbe human body responds in many ways to the invasion of pathogenic microorganisms. Discuss.this irmmune respouse, focusing on three main areas: Front-line defenses, Inflämmatiön, and'Antibody. Production

Answer 1

Immunity is the ability of an indivisual to resist development of disease and allergy even after having received infective dose of pathogen with complete virulence and the various allergens. Immune system is the system of animal body which protects it from various pathogens/infectious agents/allergens. The agents which invite action of immune system are microorganisms, their products, certain food items, chemicals, drugs, pollen, and pollutants. The body defence system or immunity is of two types; innate (nonspecific) and acquired (specific).

INNATE IMMUNITY : It is natural and non specific body defence system of the body with which an indivisual is born and which is always available to protect the body against various types of discomfort causing environmental agents.This is done by having barriers to prevent entry of foreign agents and dispose off them as soon as they enter into the body. It doesnot involve antigenic recognition. It is also called inborn, familial or natural immunity. There are a number of components of innate immunity --- physical, physiological barriers constitute the first line of body defence. Phagocytic barriers, inflammatory barriers, natural killer cells and complement system constitute the second line of body defence.

ANTIBODY- MEDIATED/HUMORAL IMMUNITY

B- lymphocytes are activated either by T- cells or directly by antigen. The activated B--lymphocytes enlarge, form plasmoblasts and then plasma cells. Plasma cells are rich in endoplasmic reticulum. In the presence of antigen the plasma cells form antibodies at the rate of 2000 molecules per cell/per second. a total some of 20 trillions per day .

Action of antibodies are Neutralisation, Agglutination, Opsonisation, Complement mediated cell lysis and Phagocytosis.