Immune System Flashcards
What are the general functions of the immune system?
Surveillance: Respond to infections, repair damaged tissues, and prevent cancer development.
- Humoral immunity: Involves substances secreted into bodily fluids.
- Cell-mediated immunity: Involves immune cells directly attacking pathogens.
What are the physical and chemical barriers of the innate immune system?
Physical barriers: Skin, mucous membranes, and cilia.
• Chemical barriers: Mucous, stomach acidity, and microbicidal substances like lysozyme.
How does the innate immune response differ from the adaptive immune response?
Innate immunity: Non-specific, rapid, and responds to infections without memory.
• Adaptive immunity: Specific, slower to develop, has memory, and responds to infections with precision.
Q4: What are the key cells involved in the innate immune response?
Neutrophils: Highly phagocytic, die after engulfing pathogens.
- Macrophages: Phagocytize pathogens, reside in tissues, and survive for weeks.
- Natural Killer (NK) cells: Target virally infected or tumor cells.
- Eosinophils: Contain cytotoxic proteins to kill parasites.
What are the main cells of adaptive immunity?
cells: Produce antibodies and provide humoral immunity.
- T cells: Provide cell-mediated immunity and include helper, cytotoxic, regulatory, and memory cells.
How do B cells and T cells differ in their roles in the immune response?
• B cells: Activated by antigens and helper T cells; secrete antibodies that neutralize pathogens or facilitate phagocytosis.
• T cells: Directly attack pathogens or recruit other immune cells, with specific receptors for antigen recognition.
What are antibodies, and how do they function in immune defense?
Antibodies: Immunoglobulins that bind to antigens, neutralizing them or marking them for phagocytosis (opsonization).
What is V(D)J recombination, and how does it contribute to immune diversity?
A:
• A process where gene segments in B cell and T cell receptors are rearranged to create diversity, enabling recognition of a vast array of antigens.
What is the role of antigen-presenting cells (APCs) in linking the innate and adaptive immune responses?
APCs (e.g., macrophages, dendritic cells, B cells) capture and process antigens, then present them to T cells to activate the adaptive immune response.
What are the primary lymphoid organs, and what is their function?
Bone marrow: Site of origin and initial maturation of lymphocytes.
- Thymus: Site where T cells mature and develop immunological self-tolerance.
What are secondary lymphoid organs, and what role do they play in the immune system?
Lymph nodes: Filter lymph and activate lymphocytes.
- Spleen: Filters blood and removes aged or defective red blood cells.
- Mucosa-associated lymphoid tissue (MALT): Includes tonsils, ileum, and appendix, where immune responses occur at mucosal surfaces.
How do lymph nodes facilitate immune responses?
Lymph nodes act as filters, trapping foreign matter and allowing lymphocytes to interact with antigens presented by APCs.
• Follicles in the lymph nodes are where B cells are activated, while T cells surround the follicles.
What is the function of the spleen in immune responses?
White pulp: Contains white blood cells involved in immune responses.
• Red pulp: Filters and removes defective red blood cells from circulation.
What is the role of MALT in the immune system?
MALT (e.g., tonsils, appendix, ileum) contains lymphocytes that provide immune surveillance at mucosal surfaces, which are vulnerable to pathogens.
Q15: What is the process of T lymphocyte activation?
Antigen-presenting cells (APCs) present antigen to T cells in lymphoid tissues.
- T cells recognize the antigen with their specific receptor and become activated to initiate the immune response.
