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Rabu, 20 Maret 2013

Gastro Intestinal Immune System


Gastro Intestinal  Immune System




 
Gastro Intestinal  Immune System


Cells of immune system

Lymphocytes are the most important type of cells of the immune system. These are produced in the bone marrow. Some of these lymphocytes migrate to the thymus gland and are called T-cells, whereas others continue to develop in the bone marrow and are called B-cells.
Out of the B-cells and T-cells, the former produce the antibodies and the latter impart cellular immunity.

B-cells and T-cells are set into action when a foreign antigen enters into the body. The B-cells are stimulated to produce antibodies. Once an antigen-specific B-cell is activated, it continues to multiply at a faster rate to produce a clone of B-cells. These are called as the plasma cells.

In a similar way, when a
T-cell responds to any specific antigen, it multiplies rapidly to form a clone of T-cells which are differentiated to be of following types.

Lymphocytes white blood cells that develop in bone marrow and circulate throughout the body in the lymphatic system , are a vital part of the immune system. Lymphocytes can be divided into two subgroups: 
      B lymphocytes and T lymphocytes. B lymphocytes (or B cells) produce immunoglobulins also called antibodies These protein molecules attach themselves to specific antigens and work with another type of white blood cell, called phagocytes—scavenger cells that surround and digest infected cells or microorganisms—to destroy the invaders. T lymphocytes (or T cells) help control the immune response and destroy foreign antigens directly.

The activity of B cells and T cells targets specific antigens
      This means that each time a new kind of antigen invades the body, the immune system must produce a new round of B cells and T cells, which attack only that antigen. It is estimated that the immune system can create more than 100 million types of antibodies. 

 As B cells and T cells mature, they begin to recognize which tissues belong in the body and which do not. These cells become "memory" cells that remember a particular antigen, so that the next time it appears, the immune response can mobilize quickly. In some cases, people have permanent immunity to a disease; for example, people who contract chicken pox usually will not have it again—or, if they do, they will have a much more mild case. 


Sumber : Bpk. Dr. Iskandar Zulkarnain

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