immune system 2 Flashcards
what are the 2 main cell immunity divsions?
innate cells (born with the immunity)
adaptive cell (provides a targeted response to specific pathogens, characterised by its ability to remember past infections- allowing for a quicker and more effective response)
what are the main 2 type of cells from the adaptive immune system
humoral- b cells
cell mediated- t cells such as: cytoxic, helper, suppressor, memory.
what is type 1 hypersensitive reaction?
immediate allergic responses mediated by IgE and characterized by rapid onset of symptoms upon re-exposure to an allergen.
what is the IgE in immunity?
antibody that is key in mediating allergic responses and protecting against certain parasitic infections, making it an important component of the immune system.
igE is involved in type 1 hypersenitivity reactions. when an individual is exposed to an allergen, their immune system may produce IgE antibodies specific to that allergen. IgE bind to the surface of mast cells and basophils.
what are the main type 1 hypersensitivity reactions
asthma,
anaphylaxis,
allergic rhinitis (hay fever)
food allergies
what are the steps in which type 1 hypersensitivity reactions happen with asthma?
- inhale irritant
- over proportion reaction (to much histamine released, causes the allergic reaction)
- IgE antibodies bind to the mass cells, mass cells which contain histamine, bradycinin and prostaglandin.
- this causes degranulation (mass cells break up, histamine is released into the blood- to much histamine)
- this causes symptoms such as vasodilation, increased permeability of the blood vessels- edema. (as fluid is leaking out of the vessels, swelling of the face, tounge, mouth and throat.
- contractions causing bronchoconstriction in asthma, itching, rashes, hives from edema
what is the first phase in hypersensitivity type 1?
sensitization phase:
the first time a person is exposed to an allergen, their immune system may react by producing specific antibodies called IgE. the IgE antibodies bind to the mast cells and basophils which are types of immune cells found in various tissues
what is the second phase in type 1 hypersentivity?
subsequent exposure:
upon re- exposure to the same allergen, the allergen binds to the IgE antibodies that are attached to the surface of the mast cells and basophils. this cross- linking to IgE triggers the actuvation of these cells
what is the 3rd phase in type 1 hypersensitiviity?
release of mediators:
activated mast cells and basophils release a variety of chemical mediators, the most well known being histamine.
other mediators include leukotrienes, prostaglandins and cytokines.
this is responsible for the symptoms
what is the 4 stage in type 1 hypersentivity?
physiological effects:
the release of these mediators leads to symptoms:
vasodilation: blood vessels widen causing redness and warmth
increased vascular permeability: this allows fluid to leak into surrounding tissues, leading to swelling (edema)
bronchoconstriction: smooth muscle contraction in the airways can lead to difficulty breathing.
mucous production:
what is inflammation and when does it occur?
cruical part of the immune systems response to injury, infection or harmful stimuli.
what is the purpose of inflammation?
serves as a protective mechanism that helps the body to eliminate the inital cause of cell injury, clear out dead cells and initiate tissue repair.
helps prevent the spread of infection and promotes healing
what are the signs and symptoms of inflammation?
redness- caused by increased blood flow to the area
heat- blood flow to the area
swelling- resulting from the accumulation of fluid and immune cells in the tissue
pain- caused by the release of chemical mediators that stimulate nerve endings by pressure from swelling
what are the 7 steps in inflammation?
- recognition of injury or infection.
- release of chemical mediators-
histamine, released mainly by mast cells, increases blood vessel permeability and promotes vasodilation, allowing more blood flow to the affected areas. - increased blood flow:
the dilation of blood vessels leads to increased blood flow to the site of injury causing redness and warmth. the increased permeability allows plasma protiens and immune cells to exit the blood stream and enter the tissue
4.recruitment of neutrophils:
first responders to the site of inflammation. they are attracted to the area by chemotactic signals released by damaged tissues and other immune cells. neurophils help to engulf and destroy pathogens,.
- activation of macrophages:
arrive at the site either from the bloodstream or by differentiating from monocytes that migrate into the tissue. they play a crucial role in phagocytosis, clearing debris, and seceting additiional cytokines to recruit other immune cells - resolution of inflammation:
once the harmful agents is eliminated, anti inflammatory signals are released to promote the healing process and resolve the inflammation. macrophages can also clear apoptotic cells and debris, facilitating tissue repair - tissue repair
what are the main 7 steps in inflammation?
recognition of injury
release of chemical mediators
increased blood flow
recruitment of neutrophils
activation of macrophages
resolution of inflammation
tissue repair
