CHAPTER 16: INNATE IMMUNITY Flashcards
Q: What is the difference between innate and adaptive immune responses?
A:
* Innate Immunity: Non-specific, immediate, no memory, includes physical and chemical barriers, and phagocytosis.
* Adaptive Immunity: Specific, slower to develop, has memory, includes T cells, B cells, and antibodies.
Q: What components are part of the first line of defense?
A:
* Physical factors: Skin, mucous membranes, cilia, saliva, tears.
* Chemical factors: Lysozyme in tears and saliva, stomach acid, antimicrobial peptides.
Q: What are the leukocytes involved in the second line of defense?
A:
* Granulocytes:
* Neutrophils: Phagocytize microbes.
* Basophils: Release histamine, involved in allergic responses.
* Eosinophils: Target parasitic infections.
* Agranulocytes:
* Macrophages: Phagocytosis and antigen presentation.
* Dendritic cells: Antigen-presenting cells (APCs).
* Natural Killer (NK) cells: Kill infected or cancerous cells.
Q: What are Toll-Like Receptors (TLRs), and what do they bind to?
A: TLRs are proteins on immune cells that recognize pathogen-associated molecular patterns (PAMPs) and trigger immune responses.
Q: What are the 7 steps of phagocytosis?
A:
1. Chemotaxis
2. Adherence
3. Ingestion
4. Formation of the phagosome
5. Fusion with lysosome (phagolysosome)
6. Digestion
7. Discharge of waste
Q: What cells are phagocytes?
A: Neutrophils, macrophages, and dendritic cells.
Q: What are the 6 ways microbes evade phagocytosis?
A:
1. Inhibit adherence (e.g., capsules).
2. Kill phagocytes (e.g., leukocidins).
3. Escape phagosomes.
4. Prevent phagosome-lysosome fusion.
5. Survive in the phagolysosome.
6. Biofilm formation.
Q: What are the signs and purposes of inflammation?
A:
* Signs: Redness, heat, swelling, pain, loss of function.
* Purpose: Destroy pathogens, limit infection spread, repair tissue damage.
Q: What are the 3 steps of inflammation?
A:
1. Vasodilation and increased permeability.
2. Phagocyte migration and action.
3. Tissue repair.
Q: What is vasodilation, and how does it help the immune response?
A: Vasodilation increases blood flow, bringing immune cells and nutrients to the infection site. Excessive vasodilation can lead to dangerous drops in blood pressure.
Q: How does a fever help an infection?
A: Inhibits pathogen growth, increases immune cell activity, and speeds up tissue repair.
Q: What are the 3 ways complement can be activated?
A: Classical, alternative, and lectin pathways.
Q: What are the 3 outcomes of complement activation?
A:
1. Cytolysis: Creates membrane attack complexes.
2. Opsonization: Enhances phagocytosis.
3. Inflammation: Stimulates immune responses.
Q: How are interferons activated, and what type of infections are they useful for?
A: Activated by viral infections; interfere with viral replication and alert neighboring cells.
