C3.2 Defence against disease Flashcards
Categories of Pathogens
Bacteria, Viruses, Fungi, Protozoa, Parasitic Worms
Skin’s Role in Primary Defence
Acts as a physical barrier, secretes antimicrobial substances
Mucous Membranes’ Role in Primary Defence
Trap pathogens, contain immune cells, secretions neutralize pathogens
Blood Clotting Process
Injury triggers platelet plug formation, clotting factors activate, fibrinogen converts to fibrin, forming a stable clot
Innate vs. Adaptive Immune System
Innate: Non-specific, immediate response. Adaptive: Specific, memory-based response
Role of Phagocytes
Engulf and digest pathogens, part of innate immunity
Types of Phagocytes
Neutrophils, Monocytes, Macrophages, Dendritic Cells
Steps in Phagocytosis
- Recognition, 2. Engulfment, 3. Formation of Phagosome, 4. Fusion with Lysosome, 5. Digestion of Pathogen, 6. Expulsion of Waste
Lymphocytes in Adaptive Immunity
B and T cells target specific antigens and form memory cells for rapid future responses
Antigen and Antibody Production
Antigens prompt immune system to produce specific antibodies
B-Lymphocyte Activation by Helper T-Cells
Helper T-cells trigger B-cell activation for antigen response
Function of Activated B-Lymphocytes
Produce antibodies and memory B-cells for lasting immunity
Clonal Selection Theory
Specific B-cells activated by matching antigens for targeted response
Memory Cells in Immunity
Long-lived cells for quicker, efficient response to known antigens
Primary vs Secondary Immune Response
First exposure vs faster, stronger response on re-exposure
Role of Antigen-Presenting Cells
Present antigens to T-cells, initiating immune activation
HIV Transmission
Transmitted through sexual contact, shared needles, contaminated blood, and mother-to-child
HIV Effect on Immune System
Destroys CD4+ T lymphocytes, weakening immune defense
Antibiotics Purpose
Treats bacterial infections, ineffective against viruses
Bacterial Resistance Causes
Overuse/misuse of antibiotics, genetic mutations
Zoonotic Diseases Transmission
Spread from animals to humans via contact, food, vectors
Vaccines and Immunity
Stimulate immune response, mimic infection safely
Herd Immunity Concept
Community immunity reducing disease spread
COVID-19 Data Analysis
Involves case numbers, mortality, vaccination rates
HIV Life Cycle
Involves attachment, replication, and virus release
Antibiotic Resistance Mechanisms
Alters drug target, inactivates or expels antibiotic
Vaccine Types
Includes live, inactivated, subunit, mRNA vaccines
COVID-19 Vaccine Development
Rapid development, clinical trials, mRNA technology
