voiceover anaphylactic shock is probably one of the shocks that most people are familiar with. It’s also known as anaphylaxis. Anaphylactic shock is an allergic reaction that’s severe enough to cause shock. And of course shock is decreased tissue perfusion,.
Or in other words decreased oxygenation of tissues. There are a number of different things that can cause an allergic reaction. For example, bee stings can cause an allergic reaction, peanut allergies, food allergies, pollen can cause allergic reactions.
And so can certain medications as well. Now of course, allergies can be either very mild and seasonal such as hay fever and sometimes allergies can be so severe that it can cause shock. But how does it cause shock?.
Well first of all to answer that, I want to acknowledge that there are two types of anaphylaxis. Those that are immunologic and those that are nonimmunologic. And I’ll go ahead and start with immunologic anaphylaxis,.
Because that’s actually the most common type. In immunologic anaphylaxis, there’s some sort of allergic agent, whether it’s poison from a bee sting or a food allergy that somehow gets in to the system. And whatever this material is, it’s known as an allergen because.
It generates an allergic response. So when this allergen first gets into the body, it will interact with B cells, and not B cells like the insect, the bee right up here, but B cells as in the letter B. Now these cells are the antibody creating cells.
Of the immune system, they create antibodies. And antibodies are essentially a little Y shaped protein that is used like a signal marker to find something that’s foreign, foreign material. So in this case, the antibodies will be reacting to the allergen.
Now antibodies that are created in response to an allergen, are known as IgE. IgE stands for immunoglobulin E. Globulin means protein and immuno just means immune. So really it’s immune protein and the classification is E. Now the reason I want to emphasis this,.
Type I hypersensitivity IgEmediated hypersensitivity causes symptoms pathology
Having a hypersensitivity means that someones immune system has reacted to something in such a way that it ends up damaging them, as opposed to protecting them. There are four different types of hypersensitivities, and in the first type or type one, the reactions rely on Immunoglobulin E, or IgE antibody, which is a specific type of antibody the other major ones being IgG, IgA, IgM, and IgD. So because IgE is involved with type one hypersensitivity reactions they are also called IgEmediated.
Hypersensitivities. This type of reaction is also sometimes called immediate hypersensitivities, because the reaction happens super faston the order of minutes. So most allergic reactions are IgEmediated, and therefore most allergies are type I hypersensitivity reactions. Allergy comes from the Greek Allos which roughly means other and ergon which.
Means reactivity. Essentially, allergies are reactions to molecules from outside your own body that most people dont react toand these are specific molecules from things you might breathe or take in like foods, animal dander, bee stings, mold, drugs or medications, and pollen. You can also mount an allergic reaction to things you come in contact with on your skin like latex, lotions, and soaps.
These specific molecules are also called antigens, and when they cause an allergic reaction, theyre called allergens. An allergic reaction happens in two steps, a first exposure, or sensitization, and then a subsequent exposure, which is when it gets a lot more serious. People that react to these allergens usually have a genetic predisposition to having overreactions to unknown molecules or allergens.
This means that these people have certain genes that cause their thelper cells to be more hypersensitive to certain antigens. Since the production of these Thelper cells is genetically linked, allergies to things tend to run in families. So lets say this person breathes in some ragweed pollen, that person happens to have Thelper cells that can bind to a specific molecule on the pollen, making that molecule.
An allergen. First off, that antigen gets picked up by immune cells hanging out in the membranes along the airways, which then grab the molecule and migrate to the lymph nodes, which happens regardless of if the person is allergic or not. These cells are antigenpresenting cells, since they carry the antigen to the lymph nodes and present it to the Thelper cells living there.
Dendritic cells and macrophages are examples of antigenpresenting cells. When the person is allergic, the antigen presenting cell will also express costimulatory molecules, which are needed to mount an effective immune response. Before the Thelper cell sees the antigen though, its called a naive Thelper, since, even though its built to recognize the antigen, it hasnt actually seen it before. When the Thelper gets its hands on the antigen though, and also binds the costimulatory molecule,.
Its now been primed, and the naive thelper changes into a different sort of thelper cell. Usually in type I hypersensitivity it differentiates into a type 2 T helper cell, or just TH2 cell, and this step happens in response to various small proteins or interleukins that might be floating around at the time. Some interleukins that sway the Thelper cell into turning into a TH2 cell are interleukin.