Adaptive Immunity
Introduction
The immune system is a complex network of cells, tissues, and organs that work together to protect the body from infection. It is divided into two main parts: the innate immune system and the adaptive immune system.
The innate immune system is the body's first line of defense against infection. It is made up of cells and molecules that are always present in the body and that can quickly recognize and attack foreign invaders.
The adaptive immune system is the body's second line of defense against infection. It is made up of cells and molecules that are not always present in the body but that can be activated in response to an infection.
The Adaptive Immune Response
The adaptive immune response is a complex process that involves the activation of several different types of cells and molecules. The first step in the adaptive immune response is the recognition of a foreign antigen by a dendritic cell.
Dendritic cells are cells that are located in the skin, lungs, and other tissues that are exposed to the outside environment. When a dendritic cell encounters a foreign antigen, it engulfs the antigen and breaks it down into small pieces.
The dendritic cell then travels to a lymph node, where it presents the antigen to a T cell. T cells are cells that are responsible for recognizing and attacking foreign invaders.
If the T cell recognizes the antigen, it will become activated and begin to proliferate. The activated T cells will then travel to the site of the infection, where they will attack and destroy the foreign invader.
The Memory Response
After the adaptive immune response has been activated, the body will develop a memory response to the foreign antigen. This memory response will allow the body to quickly and effectively respond to the same antigen in the future.
The memory response is mediated by memory T cells and memory B cells. Memory T cells are T cells that have been activated in response to a foreign antigen. Memory B cells are B cells that have been activated in response to a foreign antigen and that have differentiated into plasma cells.
Plasma cells are cells that produce antibodies. Antibodies are proteins that bind to foreign antigens and help to destroy them.
Conclusion
The adaptive immune system is a powerful and complex system that plays a vital role in protecting the body from infection. The adaptive immune response is a highly specific and effective way to target and destroy foreign invaders.
The memory response allows the body to quickly and effectively respond to the same antigen in the future. This is why vaccines are so effective at preventing disease. Vaccines work by stimulating the adaptive immune system to develop a memory response to a particular antigen.
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