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Questions and Answers
What does the 3rd Line of Defense refer to?
What does the 3rd Line of Defense refer to?
What are the two features of the 3rd Line of Defense?
What are the two features of the 3rd Line of Defense?
Specificity and Memory
The specificity of the 3rd Line of Defense allows for a response to multiple pathogens.
The specificity of the 3rd Line of Defense allows for a response to multiple pathogens.
False
How do T cells recognize pathogens in Cellular Immunity?
How do T cells recognize pathogens in Cellular Immunity?
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What is the role of T helper cells (Th cells)?
What is the role of T helper cells (Th cells)?
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Which of the following is NOT a way the 3rd Line attacks pathogens?
Which of the following is NOT a way the 3rd Line attacks pathogens?
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Define Memory in Cellular Immunity.
Define Memory in Cellular Immunity.
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Match the following types of immunity with their definitions:
Match the following types of immunity with their definitions:
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What is a common characteristic of Type I Hypersensitivity?
What is a common characteristic of Type I Hypersensitivity?
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HIV attacks Th cells, macrophages, and dendritic cells.
HIV attacks Th cells, macrophages, and dendritic cells.
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How is antivenom created?
How is antivenom created?
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Study Notes
Immune System Overview
- The 3rd line of defense refers to specific immunity, which targets and destroys foreign materials.
- Features of the 3rd line include specificity (targeted response to specific pathogens) and memory (ability to remember previous infections).
Specificity
- The immune response is tailored to specific pathogens, leading to the development of unique antibodies for each virus.
- Limited cross-reactivity exists, where similar pathogens may induce a response due to shared characteristics.
Memory
- After initial exposure to a pathogen, memory cells are generated that can recognize and respond rapidly upon re-exposure.
- Tm cells coordinate a swift immune response, often neutralizing the pathogen before symptoms appear.
Mechanisms of Pathogen Attack
- The immune system employs two main strategies: Cellular Immunity (T cells) and Humoral Immunity (B cells and antibodies).
Cellular Immunity
- T cells play a critical role by directly attacking foreign cells, cancer cells, and infected host cells.
- Recognition involves Antigen Presenting Cells (APCs) that process and display foreign antigens to T cells, activating them through the Major Histocompatibility Complex (MHC).
Types of T Cells
- T Helper (Th) cells stimulate immune responses by attracting other immune cells through interleukins.
- Cytotoxic T (Tc) cells carry out direct attacks on pathogen-infected cells using toxic chemicals.
Humoral Immunity
- B cells mediate humoral immunity by producing antibodies that neutralize or mark pathogens for destruction.
- Responses follow the recognition of an antigen, leading to B cell activation and proliferation into Plasma Cells producing large amounts of antibodies.
Antibody Functions
- Antibodies can neutralize pathogens, fix complements, agglutinate enemies, or precipitate immune complexes for removal.
- The diversity in antibody types arises from processes like Somatic Hypermutation and Somatic Recombination.
Memory in Humoral Immunity
- Elevated antibody titers are maintained post-infection, providing long-term immunity.
- B memory cells (Bm cells) enable rapid responses upon re-exposure, enhancing immune efficiency.
Types of Immunity
- Natural and Artificial forms exist: Active immunity (long-term) derives from natural exposure or vaccinations, while Passive immunity (temporary) comes from maternal transfer or serum injections.
Antigen Recognition
- Antigens trigger immune responses and can be classified into free molecules or cellular antigens based on their association with cells.
- Major Histocompatibility Complex (MHC) is crucial for distinguishing self from non-self antigens.
Hypersensitivity Reactions
- Hypersensitivity occurs when the immune response is excessive, leading to conditions like allergies, autoimmunity, or alloimmunity (tissue rejection).
- Autoimmunity involves the production of autoantibodies targeting self-tissue, often triggered by molecular mimicry or abnormal exposure to antigens.
Immunodeficiency Disorders
- Primary immunodeficiencies, like SCID, result from genetic defects affecting immune cell development.
- Secondary immunodeficiencies, such as those caused by HIV/AIDS, severely compromise the immune system, increasing vulnerability to infections.
HIV/AIDS
- HIV selectively targets CD4+ T helper cells, leading to immune insufficiency.
- The latency period can extend for years, complicating prevention and treatment efforts.
Summary of Immune Response Types
- Natural Active Immunity: can be established through direct exposure to pathogens.
- Artificial Active Immunity: develops from vaccinations.
- Natural Passive Immunity: provides temporary immunity through maternal antibodies.
- Artificial Passive Immunity: also temporary, achieved through serum injections or blood transfusions.
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Description
Test your knowledge of the immune system's third line of defense with these flashcards. Learn about its specificity, memory, and how it identifies and destroys foreign materials. Ideal for students studying immunology.
