Chapter 9: Inflammation and Immunity- Key Concepts/Questions
Case study: Two teenagers, Adrienne and Pamela, went to ski camp. Adrienne had been vaccinated against the bacterium meningococcus, but Pamela had not. While they were at camp, both girls were exposed to meningococcus, but only Pamela became ill.
Answer following questions (9-14)
Case study answers:
Answers: 1. G 2. C 3. K, E 4. J 5. B 6. A, F
How do innate and adaptive immune mechanisms differ?
Innate immune mechanisms do not require any previous exposure to mount an effective response against an antigen, and a wide variety of different antigens are recognized. Adaptive, or specific, immune mechanisms respond more effectively on second exposure to an antigen, and are highly restricted in the ability to recognize antigens (pgs. 170-172, 177).
Adrianne had B and T _______ cells for meningococcus, but Pamela did not.
A. macrophages B. memory C. complement D. eosinophils E. secondary F. helper T G. phagocytic H. cytotoxic T I. perforin J. chemotactic K. primary
Antibodies against meningococcus assisted _______ cells in destroying the bacteria.
A. macrophages B. memory C. complement D. eosinophils E. secondary F. helper T G. phagocytic H. cytotoxic T I. perforin J. chemotactic K. primary
Neutrophils accumulated in response to _______ signals and attacked the bacteria.
A. macrophages B. memory C. complement D. eosinophils E. secondary F. helper T G. phagocytic H. cytotoxic T I. perforin J. chemotactic K. primary
Pamela had a _______ response to meningococcus, which took longer to produce antibodies than did Adrianne's _______ response.
A. macrophages B. memory C. complement D. eosinophils E. secondary F. helper T G. phagocytic H. cytotoxic T I. perforin J. chemotactic K. primary
The _______ that phagocytosed bacteria in both girls presented antigens to _______ cells, which secreted cytokines.
A. macrophages B. memory C. complement D. eosinophils E. secondary F. helper T G. phagocytic H. cytotoxic T I. perforin J. chemotactic K. primary
Tissue damage caused inflammation and activation of _______, which helped lyse the bacteria.
A. macrophages B. memory C. complement D. eosinophils E. secondary F. helper T G. phagocytic H. cytotoxic T I. perforin J. chemotactic K. primary
Why is an immune response usually more effective on subsequent exposure to an antigen than after the first exposure?
An immune response is usually more effective on subsequent exposure because the T-cell receptors on T lymphocytes and memory B cells are able to recognize the antigen and quickly produce the appropriate antibodies, resulting in a much faster and larger lymphocyte response. The immune response to primary exposure is usually slow and often insufficient to prevent illness (pg. 177).
How do noncellular immune system components, including antibodies, complement, and clotting factors, aid the immune response?
Antibodies bind to particular antigens and function in precipitation, agglutination, neutralization, opsonization, and complement activation. Complement activation results in inflammation and formation of membrane attack complexes that directly lyse cellular antigens. Tissue injury from the infectious process activates the coagulation cascade, which forms a fibrin meshwork to help entrap and localize the agent. The kinin system is also activated, which promotes vasodilation to increase blood flow to the area (pgs. 168-170, 184-186).
How do immune cells communicate through cell-to-cell interactions and through secreted cytokines?
Antigen-presenting cells bind to T cells which stimulate intracellular signaling pathways in the B cell and helper T cell that promote clonal expansion and differentiation. Activation of the helper T cell causes release of cytokines, which is required for B cells to proliferate and begin antibody synthesis (pg. 183).
What is the role of major histocompatibility complex (MHC) class I and II proteins in cell-mediated immunity?
Cytotoxic T cells can only recognize an antigen if it is physically bound to an MHC class I molecule, in which it is stimulated to release enzymes and pore-forming proteins that lyse the target cell. MHC class II proteins are used to present antigens obtained from extracellular sources, which are engulfed by the antigen-presenting cell. The MHC II-antigen complexes are then displayed at the cell surface, where T helper cells can detect them (pgs. 177-179).
How do macrophages, granulocytes, and lymphocytes work together to locate, recognize, and eliminate pathogens?
Macrophages and dendritic cells are commonly the first immune cells to encounter the antigen; they engulf and display the antigen on their cell surface; macrophages secrete cytokines that stimulate white blood cell (WBC) production and help WBCs locate the area. T helper cells are activated by these antigen-presenting cells and secrete cytokines that stimulate the production of WBCs in the marrow, initiate proliferation of mature B and T cells, and stimulate the phagocytic potential of macrophages and neutrophils. T cells also assist in B cell proliferation and antibody secretion (pgs. 161-168).
What are the major organs and cellular components of the body's defense against foreign antigens?
Skin and mucous membranes: monocytes and macrophages Bone marrow: B lymphocytes and leukocytes Thymus: T lymphocytes Tonsils, spleen, and lymph nodes: B and T lymphocytes Peyer patches: primarily B lymphocytes (pgs. 158-161)
