What are the 3 pathways for caspase activation (leading to apoptosis)? Correct Ans-1.
Intrinsic mitochondrial pathway
- Inactivation of Bcl2
- Lack of Bcl2 allows cytochrome c to leak out from the inner mitochondrial matrix into
cytoplasm
2. Extrinsic-ligand pathway
- FAS ligand binds FAS death receptor (CD95) on target cell OR
- TNF binds TNF receptor on the target cell
3. Cytotoxic CD8+ T-cell mediated pathway
- Perforins secreted by CD8+ cells create pores in membrane of target cell
- Granzyme from CD8+ cell enters pores and activates caspases
What deposits in primary amyloidosis? Secondary amyloidosis? Correct Ans-Primary: AL,
derived from immunoglobulin light chain
Secondary: AA, derived from serum amyloid-associated protein
What is fibrinoid necrosis? Correct Ans-Necrotic damage to blood vessel wall
- Leaking of proteins (including fibrin) into vessel wall
- Results in bright pink staining of the wall
- Characteristic of malignant hypertension and vasculitis
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What are the two general causes of acute inflammation? Correct Ans-1. Infection
- Neutrophils come in
- To eliminate pathogen
2. Tissue necrosis
- To clear necrotic debris so healing can begin
- Is followed by acute inflammation
- Repair phase of wound healing
Characteristics of Toll Like Receptors? Correct Ans-- Present on cells of the innate immunity
- Activated by PAMPs that are commonly shared by microbes
- CD14 on macrophages recognizes LPS on the outer membrane of Gram- bacteria
- TLR activation results in up regulation of NF-kappaB (nuclear transcription factor) that
activates immune response genes leading to the production of immune mediators
- Also present on cells of adaptive immunity
What are the 4 mediators of neutrophils? Correct Ans-1. LT4 (leuokotriene 4)
2. C5a
3. IL-8
4. Bacterial products
What 3 things activate macrophages? Correct Ans-1. Tissue trauma
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2. Complement proteins C3a and C5a
3. Cross-linking of cell-surface IgE by antigen
What are the 3 activation pathways for complement? Correct Ans-1. Classical pathway - C1
binds to IgG or IgM bound to antigen
2. Alternative pathway - Microbial products directly activate complement
3. Mannose-binding lectin pathway - MBL binds to mannose on microorganisms and activates
complement
What is Hageman factor? Correct Ans-Factor XII
- Activated upon exposure to sub endothelial or tissue collagen
- Activates
1. Coagulation and fibrinolytic systems
2. Complement
3. Kinin system
What are the 7 steps of neutrophil arrival and function? Correct Ans-1. Margination - Cells
marginate from center of flow to periphery
2. Rolling - Selectin speed bumps are unregulated on endothelial cells
3. Adhesion - ICAM and VCAM are unregulated
4. Transmigration and chemotaxis
5. Phagocytosis
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6. Destruction of phagocytic materials
7. Resolution
What is Chediak-Higashi syndrome? Correct Ans-Microtubule defect
- AR
- Protein trafficking defect characterized by impaired phagolysosome formation
- Increased risk for pyogenic infections
- Neutropenia
- Giant granules in leukocytes
- Defective primary hemostasis
- Albinism
- Peripheral neuropathy
What 2 things characterize acute inflammation? Correct Ans-Edema
Neutrophils in tissue
What 2 things characterize chronic inflammation? Correct Ans-Presence of lymphocytes
and plasma cells in tissues
What are the 5 stimuli for chronic inflammation? Correct Ans-1. Persistent infection
2. Infection with viruses, mycobacteria, parasites, fungi
3. Autoimmune diseases