Allergic Reactions Flashcards
What is an allergy?
hypersensitive immune response to a normally harmless substance.
What is sensitization in the context of allergies?
the immune system first encounters an allergen, such as grass pollen.
What are Antigen Presenting Cells (APCs)?
APCs are immune cells that take up and degrade allergens into fragments, displaying them on their surface to initiate the allergic response.
What role do APCs play in allergic reactions?
activate immune cell called type II T helper cells (Th2).
What do Th2 cells do after activation?
Th2 cells release chemical signals that stimulate immune cell, B cells.
What is the function of B cells in allergic reactions?
B cells develop into antibody-producing plasma cells, which produce immunoglobulin E (IgE)
What is immunoglobulin E (IgE)?
IgE is a class of antibodies that is specific to the allergen encountered, such as grass pollen.
What happens upon subsequent exposure to the same allergen?
IgE binds to mast cells
triggering the release of various chemicals, including histamines.
What are mast cells?
Specialized White Blood cells located in tissues like mucous membranes and skin that play a crucial role in allergic reactions.
What is the significance of IgE binding to mast cells?
The binding of IgE to mast cells is crucial for the manifestation of allergic symptoms.
What is sensitization?
Sensitization is the initial immune response to an allergen.
What is the role of Th2 activation?
Production of IgE antibodies.
