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
#posting tugas cyberprenership
ahmad baihaqi
NIM 1112503964
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