The Innate Immune System Is The Defense Mechanism Essay

1340 Words Dec 17th, 2014 null Page
The innate immune system is the defense mechanism that is activated immediately or shortly after the body is exposed to invading microorganisms.1 This system is quick in response and does not have a memory, meaning it doesn’t need previous exposure to the foreign microbe’s antigen before it can be activated.2 The adaptive immune system consists of antigen-specific immune responses.2 This system is slow in response because after it is exposed to an antigen, it needs time to process the antigen and then recruit the proper cells to elicit an immune response.2 Thus the adaptive immune system requires more time.2 The adaptive immune system does have a memory because subsequent exposure to the same antigen will trigger a much faster response.2 Innate immunity can be found on the skin and on the surfaces of mucous membranes.3 The B and T cells of the adaptive immune system are found in the peripheral lymphoid organs, the spleen, the lymph nodes, and in lymphoid tissues associated with mucosa, such as the tonsils and appendix.4
2. The immune cells all originate from pluripotent hematopoietic stem cells in the bone marrow.4 The pluripotent hematopoietic stem cells then divide into two specialized stem cells, a common lymphoid progenitor and a common myeloid progenitor.4 The common lymphoid progenitor gives rise to the B and T cells.4 The common myeloid progenitor continues to divide to form a granulocyte and macrophage progenitor.4 These cells give rise to…

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