Immune System
From DrugPedia: A Wikipedia for Drug discovery
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| - | The '''immune system''' is a network of cells, tissues, and organs that work together to defend the body against attacks by “foreign” invaders like bacteria, parasites, and | + | The '''immune system''' is a network of cells, tissues, and organs that work together to defend the body against attacks by “foreign” invaders like bacteria, parasites, fungi and viruses. The human body provides an ideal environment for many microbes. |
The immune system is amazingly complex. It can recognize and remember millions of different enemies, and it can produce secretions (release of fluids) and cells to match up with and wipe out nearly all of them. | The immune system is amazingly complex. It can recognize and remember millions of different enemies, and it can produce secretions (release of fluids) and cells to match up with and wipe out nearly all of them. | ||
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| + | An antigen is any substance that elicits an immune response, from a virus to a sliver. | ||
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==Self and Nonself== | ==Self and Nonself== | ||
The key to a healthy immune system is its remarkable ability to distinguish between the body’s own cells, recognized as “self,” and foreign cells, or “nonself.” The body’s immune defenses normally coexist peacefully with cells that carry distinctive “self” marker molecules. But when immune defenders encounter foreign cells or organisms carrying markers that say “nonself,” they quickly launch an attack. | The key to a healthy immune system is its remarkable ability to distinguish between the body’s own cells, recognized as “self,” and foreign cells, or “nonself.” The body’s immune defenses normally coexist peacefully with cells that carry distinctive “self” marker molecules. But when immune defenders encounter foreign cells or organisms carrying markers that say “nonself,” they quickly launch an attack. | ||
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| + | ==Types of Immunity== | ||
| + | Immunity can be either | ||
| + | * natural or artificial | ||
| + | * innate or acquired\adaptive | ||
| + | * active or passive | ||
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| + | '''Active natural''' (contact with infection): develops slowly, is long term, and antigen specific. | ||
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| + | '''Active artificial''' (immunization): develops slowly, lasts for several years, and is specific to the antigen for which the immunization was given. | ||
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| + | '''Passive natural''' (transplacental = mother to child): develops immediately, is temporary, and affects all antigens to which the mother has immunity. | ||
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| + | '''Passive artificial''' (injection of gamma globulin): develops immediately, is temporary, and affects all antigens to which the donor has immunity. | ||
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| + | ==Major components of the immune system== | ||
| + | |||
| + | * Thymus | ||
| + | * Spleen | ||
| + | * Lymph system | ||
| + | * Bone marrow | ||
| + | * White blood cells | ||
| + | * Antibodies | ||
| + | * Complement system | ||
| + | * Hormones | ||
| + | |||
| + | == Major Cells of Immune System== | ||
| + | The cells that are part of this defense system are white blood cells, or '''leukocytes'''. They come in two basic types which combine to seek out and destroy the organisms or substances that cause disease. | ||
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| + | There are two kinds of lymphocytes: | ||
| + | |||
| + | * B lymphocytes | ||
| + | * T lymphocytes. | ||
| + | |||
| + | Lymphocytes start out in the bone marrow and either stay there and mature into B cells, or they leave for the thymus gland, where they mature into T cells. | ||
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| + | B lymphocytes and T lymphocytes have separate jobs to do. | ||
| + | |||
| + | * B lymphocytes are like the body's military intelligence system, seeking out their targets and sending defenses to lock onto them. | ||
| + | |||
| + | * T cells are like the soldiers, destroying the invaders that the intelligence system has identified. | ||
Revision as of 10:09, 11 August 2008
The immune system is a network of cells, tissues, and organs that work together to defend the body against attacks by “foreign” invaders like bacteria, parasites, fungi and viruses. The human body provides an ideal environment for many microbes.
The immune system is amazingly complex. It can recognize and remember millions of different enemies, and it can produce secretions (release of fluids) and cells to match up with and wipe out nearly all of them.
An antigen is any substance that elicits an immune response, from a virus to a sliver.
Contents |
Self and Nonself
The key to a healthy immune system is its remarkable ability to distinguish between the body’s own cells, recognized as “self,” and foreign cells, or “nonself.” The body’s immune defenses normally coexist peacefully with cells that carry distinctive “self” marker molecules. But when immune defenders encounter foreign cells or organisms carrying markers that say “nonself,” they quickly launch an attack.
Types of Immunity
Immunity can be either
- natural or artificial
- innate or acquired\adaptive
- active or passive
Active natural (contact with infection): develops slowly, is long term, and antigen specific.
Active artificial (immunization): develops slowly, lasts for several years, and is specific to the antigen for which the immunization was given.
Passive natural (transplacental = mother to child): develops immediately, is temporary, and affects all antigens to which the mother has immunity.
Passive artificial (injection of gamma globulin): develops immediately, is temporary, and affects all antigens to which the donor has immunity.
Major components of the immune system
- Thymus
- Spleen
- Lymph system
- Bone marrow
- White blood cells
- Antibodies
- Complement system
- Hormones
Major Cells of Immune System
The cells that are part of this defense system are white blood cells, or leukocytes. They come in two basic types which combine to seek out and destroy the organisms or substances that cause disease.
There are two kinds of lymphocytes:
* B lymphocytes * T lymphocytes.
Lymphocytes start out in the bone marrow and either stay there and mature into B cells, or they leave for the thymus gland, where they mature into T cells.
B lymphocytes and T lymphocytes have separate jobs to do.
- B lymphocytes are like the body's military intelligence system, seeking out their targets and sending defenses to lock onto them.
- T cells are like the soldiers, destroying the invaders that the intelligence system has identified.
