IMMUNOLOGY

Detailed explanation-1: -Antibodies are protective proteins produced by your immune system. They attach to antigens (foreign substances)-such as bacteria, fungi, viruses and toxins-and remove them from your body.

Detailed explanation-2: -Antibodies are proteins made by the body’s natural defence system (immune system) to fight foreign substances, such as bacteria. Antibodies attach themselves to the foreign substance, allowing other immune system cells to attack and destroy the substance.

Detailed explanation-3: -The antibodies destroy the antigen (pathogen) which is then engulfed and digested by macrophages. White blood cells can also produce chemicals called antitoxins which destroy the toxins (poisons) some bacteria produce when they have invaded the body.

Detailed explanation-4: -1) Antibodies are secreted into the blood and mucosa, where they bind to and inactivate foreign substances such as pathogens and toxins (neutralization). 2) Antibodies activate the complement system to destroy bacterial cells by lysis (punching holes in the cell wall).

Detailed explanation-5: -A protein made by plasma cells (a type of white blood cell) in response to an antigen (a substance that causes the body to make a specific immune response). Each antibody can bind to only one specific antigen. The purpose of this binding is to help destroy the antigen.

Detailed explanation-6: -Macrophages and neutrophils (phagocytes) are the front-line defenders in your body’s immune system. They seek out, ingest, and destroy pathogens and other debris through a process called phagocytosis.

Detailed explanation-7: -Cells bound by such antibodies can then be killed by a specialized non-T, non-B lymphoid cell called a natural killer cell (NK cell), which we met earlier in Chapter 2. NK cells are large lymphoid cells with prominent intracellular granules; they make up a small fraction of peripheral blood lymphoid cells.