immunology 2 Flashcards
(11 cards)
What is the key difference between innate and adaptive immunity?
Innate immunity is non-specific and present from birth, while adaptive immunity is specific and develops after exposure to pathogens.
What substances and cells participate in adaptive immunity?
Antibodies, B cells, T cells (helper and cytotoxic), and antigen-presenting cells (macrophages, dendritic cells).
What is the structure of an antibody?
Y-shaped protein with two identical heavy chains and two identical light chains, with variable regions that bind antigens.
What is the function of antibodies in adaptive immunity?
They recognize and bind antigens to neutralize pathogens or mark them for destruction.
What is the role of MHC molecules in adaptive immunity?
MHC I presents intracellular antigens to CD8+ cytotoxic T cells, MHC II presents extracellular antigens to CD4+ helper T cells.
How do B cells function in the immune system?
B cells recognize antigens, proliferate, and differentiate into plasma cells (which produce antibodies) or memory B cells.
What is clonal selection and why is it important?
It’s the process where only B or T cells with receptors specific to an antigen are activated, forming memory cells for faster response upon re-exposure.
How do macrophages contribute to adaptive immunity?
They act as antigen-presenting cells that link innate and adaptive immunity by presenting antigens to T cells.
How do vaccines work?
Vaccines stimulate the adaptive immune system by exposing it to a weakened or modified form of a pathogen to induce memory cell formation.
What are hypersensitivity reactions?
Excessive or inappropriate immune responses to antigens, including allergies and autoimmunity.
What is immunodeficiency?
A condition where parts of the immune system fail or are missing, leading to increased risk of infections (e.g., SCID, AIDS).
