Immunology

Chapter 15 The Immune System

In chapter 15 we learned about the bodies response to a pathogen. The immune system is split into Innate immunity or non-specific and Adaptive or specific immunity. The innate immunity is inherited. For example the epithelial membrane, gastric juices or phagocytes. The second is Adaptive. This type is specific to the intruder. This is from prior exposure to the germ or disease.

This is a quick diagram and explanation of the participants of the immune system



Your immune system is responsible for helping eliminate invading organisms. The key cells in your immune system are lymphocytes known as B cells and T cells, which originate in your bone marrow. After T cells further develop in your thymus, all of your immune system cells gather in your lymph nodes and spleen. Antigens (triangular shapes above) are ingested (1), partially digested (2) and then presented to helper T cells by special cells called macrophages (3). This process activates the helper T cells to release hormones (lymphokines) that help B cells develop. (4) These hormones, along with recognition of further antigens (5), change the B cell into an antibody-producing plasma cell (6). The antibodies (Y shapes above) produced can be one of several types (IgG, IgM, IgA, IgE and IgD) (7). The antibody "fits" the antigen much like a lock fits a key. The antigen is thus rendered harmless. The helper T cells also aid in development of cytotoxic T cells (8), which can kill antigens directly; memory T cells are produced (9) so that re-exposure to the same antigen (10)will provide a more rapid and effective response.

This information was taken from the mayo clinic staff: http://images.google.com/imgres?imgurl=https://www.bcbsri.com/BCBSRIWeb/images/image_popup/r7_immunesystem.jpg&imgrefurl=https://www.bcbsri.com/BCBSRIWeb/images/mayo_popup/Yourimmunesystem.jsp&usg=__2c5zhi73FXGZ8dUi7-Jh-LKYJGI=&h=417&w=399&sz=35&hl=en&start=13&sig2=a47192mzdfTeAzB4wRNlcg&um=1&itbs=1&tbnid=ESLg3vuGUJRb7M:&tbnh=125&tbnw=120&prev=/images%3Fq%3Dimmune%2Bsystem%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26hs%3DKAZ%26sa%3DN%26rls%3Dorg.mozilla:en-US:official%26tbs%3Disch:1&ei=DKKfS7DcFYzYNu_DwZ0L

Active and Passive Immunity
Active Immunity and Clonal Selection Theory: When a person is exposed to a pathogen for the first time, there is a 5-10 day period before the antibodies appear in the blood. During the second expose to the pathogen the response is much faster. According to the Clonal Selection Theory the B lymphocytes inherit the ability to produce particular antibodies.

Passive Immunity refers to the immune protection that can be produced by the transfer of antibodies to a recipient from a human or animal donor.

=Tumor Immunity= Tumor cells can reveal antigens that stimulate the destruction of the tumor. If a tumor spreads we call this metastasis. If a tumor is non-cancerous it is called benign and if it is cancerous it is called malignant.

Lastly we learned about disease caused by the immune system. Autoimmune diseases are those that are caused by the failure of the immune system to recognize and tolerate self-antigens.

6 reasons why

1. Antigen that does not normally circulate in the blood may be exposed to the immune system 2. A self- antigen that is otherwise tolerated may be altered by combining with a foreign hapten 3. Antibodies may be produced that are directed against other antibodies 4. Antibodies produced against foreign antigens may cross-react with self-antigens. 5. Self- antigens such as receptor proteins, may be presented to the helper T cells together with class 2 MHC molecules 6. Autoimmune disease may result when there is inadequate activity of regulatory suppressor T lymphocytes.

Allergies
Immediate hypersensitivity- abnormal B lymphocyte response Delayed hypersensitivity- abnormal T cell response

Questions: Active Immunity VS passive immunity: Active is the deliberate exposure to the disease- bringing someone around chicken pox to get it over with. Passive is receiving immune protection from a donor, ready made antibodies. Innate VS Adaptive: Innate is inherited it is already in the body. Adaptive is being exposed to the pathogen and then developing immunity to it. Cell mediated VS Humoral Immunity: Cell mediated is is an immune response that does not involve antibodies or complement but rather involves the activation of macrophages. Humoral immunity is s the aspect of immunity that is mediated by secreted antiboides (as opposed to cell-mediated immunity which involves T lymphocytes).

Local Inflammation response: Bacteria break in, complement protein are activated during humoral immunity by B lymphocytes, Activated complement increases attracting the phagocytes, next lymphocytes are stimulated to produce antibodies against the antigen. This amplifies the previous response, which promotes phagocytic activity of neutophils, macrophages and moncytes. This draws the leukocytes toward the site of infection. The leukocytes squeeze between the adjacent endothelial and enter the connective tissue. They interact with surrounding molecules that guide the leukocytes to the infection. During an injury neutrophils arrive first and release a chemical signal that recruits the monocytes, lymphocytes and other immune cells. Through the action of protease the neutrophils create pus, which closes capillaries preventing the spread of the infection. Macrophages destroy the infection. Mast cells produce heparin with cause clotting. Mast cells release histamine to clot the blood. Histamine causes redness and warmth which are signs of inflammation.



http://www.goodpsych.com/storage/inflammation.jpg

Personal Application: This chapter is relevant to me because we will be working with clients that have open wounds or healing fractures and we need to inspect the skin for infection before we are able to treat our patients. This chapter taught me the different stages of healing and about the immunity of the body.