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Immunity is the ability of the body to fight pathogens, like viruses, bacteria, and fungi; but, also, foreign substances, like toxins and chemicals. Now, the immune system consists of two main branches: innate immunity and adaptive immunity. Innate immunity is the first line of immunity, that we are born with; it is fast, meaning that it responds within several minutes to hours; it’s non-specific, therefore it does not differentiate one pathogen from another; and finally, it’s short-lived, meaning it does not retain the memory of previous infections. On the flip side, adaptive immunity is the second line of defense, that is acquired throughout life; it is slower and takes time to respond; but it’s also specific, so it recognizes different pathogens; and long-term, so it doesn’t forget a previous exposure to a pathogen.
In the active adaptive immune response, antibodies are produced by the client’s own immune system, following exposure to a particular antigen. In this case, two mechanisms can be employed: the humoral response, where antibodies are secreted by B cells; and the cell-mediated response which is carried out by T cells. Both B and T cells are a type of white blood cell called lymphocytes, and they’re produced in the bone marrow. B cells are called “B” cells because they mature in the bone marrow, while T cells are called “T” cells because they mature in the thymus.
Now, when mature B cells leave the bone marrow they’re still naive, meaning they haven’t been exposed to an antigen yet; so they usually circulate around in the blood or find their way to the lymph nodes or spleen. Once they encounter an antigen, they become memory B cells, or plasma cells, which secrete specific antibodies against the antigen.
The adaptive immune response is a complex network of cells and molecules that work together to protect the body from infection. This response is "adaptive" because it adjusts its tactics as needed to fight off different pathogens. The immune system also produces Memory B cells and Memory T cells, which remember how to fight a particular pathogen if it ever comes back.
Nurses are essential members of the healthcare team who help patients through every stage of their illness. They provide care, education, and support to patients and their families, and work with other healthcare professionals to ensure that patients receive the best possible care.
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