08+Immunology

Immunology Chapter 15



__//**Content Summary **//__

//When it comes to defense systems that the human body has there are many. The specific defense mechanisms that the body uses are both simple and intricate. They can either be internal or external. The two types of immunity are specific and nonspecific. Specific immunity directly relates to the actions of lymphocytes, and these lymphocytes pertain to one specific molecule or individual parts of molecules called antigens. Nonspecific immunity can be classified as mechanisms such as phagocytosis or the release of interferons. The three most interesting points in this chapter to me were the defense mechanisms, active and passive immunity, and the diseases that are caused by the immune system. // Source (Physiology Book)

//The defense system starts before you even enter the body, but inside the body the defense mechanisms are almost countless. Nonspecific or innate defense mechanisms can be as simple as a phagocytic cell devouring a foreign pathogen. The nonspecific mechanisms are similar to a bouncer at a popular club. They know who is and is not supposed to be there. The defense mechanisms respond to foreign objects that enter the body without permission and mark them so that they can be destroyed or removed from the body immediately. Specific or adaptive immunity also responds to foreign objects. However these specific foreign objects are considered antigens. Antigens are molecules or parts of them that are highly intricate and large. Any given molecule can contain several sites that can trigger the production of antibodies. Another identifier of specific immunity is the fact that it is driven by lymphocytes. There are two main types of lymphocytes that are the warriors of the immune system, these are the B and the T lymphocytes. B lymphocytes are related to humoral immunity and can secrete antibodies, whereas the T lymphocytes are directly tied into cell-mediated immunity. These two immunities do not act alone, and they often conspire to eliminate a common enemy and in doing so create inflammation. // Source (Physiology Book)

[|The Immune System]

//The invasion of the body by a foreign pathogen causes the body to respond in two waves of responses. The primary response is the first wave that is the immediate reaction from the body when it senses the invasion. The secondary response follows shortly after. The secondary response is where the IgM antibodies are being produced slowly and the individual is very likely to be getting sick. The IgG antibodies are being produced at the same time, but they are being produced at a rapid rate. When a person is exposed to an active immunization they are actually being exposed to the actual sickness that they are trying to avoid. But in this case the immunization that they are being given is a weaker version than the wild version of the virus. The secondary action comes as a result of the multiplication of the lymphocytes as caused by the antigen stimulation. // Source (Physiology Book)

//One of the most deadly health related issues is the autoimmune disease. When this happens the body is supplying itself with its own pathogens that then destroy their own antigens. Antibodies are being created just to attach and kill of the body’s supply of antigens. This is the same sort of reaction that happens when someone receives a blood transfusion from someone who has a conflicting blood type. //

//There are two main types discussed in this chapter which are the immediate hypersensitivity and the delayed hypersensitivity. During the immediate hypersensitivity the antibodies attach to the mast cells and cause the mast cells to release chemicals. Histamines and leukotrienes, along with prostaglandins are believed to create the allergic reaction. Delayed hypersensitivity is a cell mediated reaction in the response of T lymphocytes. //

__//**Application **//__ //Immunity is another thing that can relate to anyone of any profession, but can have a little more meaning in the nursing field. The importance of immunity is something that is probably overlooked and under rated all too often. The nursing field does not necessarily apply more to the immunity, but it is in focus a little more than some other professions. The only reason that it is like this is because it is one main focus of being a nurse. Nurses often administer vaccines to their doctor’s patients. Vaccines help to build and enhance the individual’s immunity by giving them dead antigens to fight off. The body creates antibodies to fight off these antigens, and then stores the plans for making them. When the real bacteria tries to enter the body, the body calls for those plans and makes the desired antibodies to fight off the specific antigens. Not only is the importance of the patients immunity great, so is that of the nurse as well. The nurse must have a decent immunity built up as well in order to even be a nurse by profession. If a nurse were to have a poor immunity, making it to work would be difficult because they are always around sick people and would most likely end up getting sick often. //

__//**Essential Questions **//__ //Active vs. Passive Immunity- Active immunity is the immunity that one forms over a lifetime. It is the immunity that you gain as you get sick. Once one gets sick they learn how to produce the proper antibodies to fight off the illness, and if the same illness decides to attack again the body will be ready because it will already have a reserve of the specific antibodies. The immunity is accumulated over time and can be added to by vaccinations. Passive immunity is the immunity that you receive from another person. They are antibodies that you receive pre-made from another source. These are not produced by your body, but by another human or animals body. //

//Innate vs. Adaptive Immunity- Innate is the first line of defense when a pathogen is identified by the body. The adaptive immunity is when an immune cell shows the pathogen to a lymph node so that they can begin to produce a specific antigen to fight the illness. Innate is nonspecific and adaptive is specific immunity. The innate system involves B lymphocytes, neutrophills, and macrophages. The adaptive immunity involved T lymphocytes and MHC molecules. //

//Cell-mediated vs.Humoral Immunity- Cell-mediated and humoral immunity are the two main functional components of the acquired immune system. Both the humoral and cell-mediated immunity work together as synergists to create one effective immune system. Cell-mediated immunity is very specific in its responses and is controlled and directed by the T lymphocytes, and in contrast the humoral immunity is a more general response by antibodies. // //Inflammatory response-The first step in local inflammation is the antigens reaching the surface of the bacterial cells. Next they bind to the antibodies, which surround the bacteria. This then triggers the compliment and promotes phagocytosis by neutrophils and macrophages. The activation of the compliment also engages mast cells to realease histamine and other mediators of inflammation. Another thing it releases is the leukocytes which rush to the inflamed cite. The symptoms of local inflammation include swelling, redness, itch, and a possible fever. //