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Immune System
Objectives
Concepts to Learn
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Lines of defense
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Specific and non-specific defense
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Phagocyte
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Natural killer cell
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Anti-microbial protein
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Complement protein
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Interferon
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Inflammatory response and histamine
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Allergy
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Virus
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Antigen and antibody
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Characteristics of antibody
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Active and passive immunity
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Vaccine
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Humoral and cell-mediated immunity
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B-cell and T-cell
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TC cell and TH cell
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HIV and AIDS
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Autoimmune disorders
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1.1.Functions of Immune System
Objectives
Concepts to Learn
Q&A
What is the function of the immune system?
The immune system is evolved to defend the invasion of foreign substances that alter the function of the internal organs.
The immune system and pathogens are co-evolved together, each gets more and more sophisticated in the process. In fact, the immune system can be considered as the defense system like the military, and the pathogens are the intruders.
What is the lymphatic system?
It is continuous with the circulatory system, except that it does not contain red blood cells.
Lymphatic system is an extension of the circulatory system, and is separate from the circulatory system. It has separate lymphatic vessels, similar to the blood vessels, where lymphatic fluid is found.
What is the difference between the lymphatic system and circulatory system?
There are lymphatic nodes in the lymphatic system, whereas there is a heart in the circulatory system. The rate of flow in the lymphatic system is much slower than the circulatory system.
The lymphatic nodes are distributed in multiple places in the lymphatic system.
The flow of lymphatic fluid is very slow compared to the blood flow. Lymphatic fluid eventually drains back into the circulatory system.
How is the immune system organized?
The immune system is organized based on the first line of defense, second line of defense and third-line of defense.
The first and second lines of defense are non-specific, i.e., they merely attack the pathogens but don’t recognize specific pathogens per se.
The third line of defense is specific, which is regulated by antibodies. They are specific in the sense that they recognize specific antigens so that they can identify them specifically in their attack.
What is the strategy for the immune system to defend the body?
It makes the implicit assumption that anything that is foreign is potentially harmful to the organism; thus it will destroy them.
The defense...
