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37 Cards in this Set
- Front
- Back
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What does the Lymphatic System do?
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The Lymphatic System
Protects us against disease Lymphatic system cells respond to: -Environmental pathogens -Toxins -Abnormal body cells, such as cancers |
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What are Specific Defenses?
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-Lymphocytes
-To a specific pathogen based on antigens |
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What is immunity?
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Immunity
-The ability to resist infection and disease -Not just lymphatic system |
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What are Nonspecific Defenses?
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-Block or attack any potential infectious organism
-Cannot distinguish one attack from another |
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List the Seven Major categories of Innate (Non-specific Defenses.
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1. Physical Barriers
2. Phagocytes 3. Immunological surveillance 4. Interferons 5. Complement 6. Inflammatory response 7. Fever |
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What are the 3 Innate Defenses that are WBCs we talked about?
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Phagocytes: First line of cellular defense
Microphage: Neutrophils and eosinophils Macrophage (come from monocytes): fixed macrophage known as histocytes microglia-CNS Kupffer cells-liver free macrophage alveolar “dust” cells-lung |
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What are the 3 methods of destruction by a macrophage?
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1. engulf a pathogen
2. bind to it and call for assistance 3. destroy it with toxin chemicals (TNF (tissue necrosis factor), peroxides, NO |
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What is Immunological Surveillance?
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-Cancer Cells
-With tumor-specific antigens -Viral infections -Cells infected with viruses |
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What is Immunilogical Escape?
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-Cells don’t produce tumor-specific antigens
-Cover up antigens -Destroy NK cells |
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What are the types and functions of Inteferons?
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Alpha-interferons (produced by cells infected w/ viruses. attract and stimulate NK cells and enhance viral infection resistance
Beta-interferons (secreted by fibroblasts, slow inflammation in a damaged area Gamma interferons (secreted by t cells adn NK cells, stimulate macrophage activity |
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What is the Compliment System? What do we need to know about it?
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Complement system
Consists of circulating proteins that assist antibodies in the destruction of pathogens Bacteria have foreign antigens. Antibodies attach. C-proteins. the main we need to know is C3 which become C3b. The MAC attack. Classical Pathway -The most rapid and effective activation of the complement system occurs through classical pathway. Effects of Complement Activation -Antigen-antibody-C1...C3-C3B (active form) -Pore formation -Destruction of target plasma membranes -Form membrane attack complex (MAC) |
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What are the Cardinal signs and symptoms of inflammation?
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-Swelling (tumor)
-Redness (rubor) -Heat (calor) -Pain (dolor) |
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What is inflammation?
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Also called inflammatory response
A localized response Triggered by any stimulus that kills cells or injures tissue |
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Explain the tissue repair pathway.
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Tissue Damage causes Chemical change in interstitial fluid which causes Mast Cell Activation, which release histamine and heparin.
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What is Fever?
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An elevation of body temperature that accelerates tissue metabolism and the activity of defenses
-A maintains body temp above 37C 99F -Pyrogens -Any material that causes the hypothalamus to raise body temperature |
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What are Specific Defenses?
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T Cells
-Provide cell-mediated immunity -Defend against abnormal cells and pathogens inside cells B Cells -Provide antibody-mediated immunity -Defend against antigens and pathogens in body fluids |
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What are the 4 Characteristics of Immunity of the specific defenses?
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-Specificity
-Versatility -Memory -Tolerance |
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What are the two main divisions of Immune response?
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-Two main division
1. Cell-mediated immunity (T cells) 2. Antibody-mediated immunity (B cells) |
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What are the 4 major types of T cells?
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1. Cytotoxic T cells (also called Tc cells)
-attack cells infected by viruses -responsible for cell-mediated immunity 2. Memory T cells -Clone more of themselves in response to “remembered” antigen 3. Helper T cells (also called TH cells) -Stimulate function of T cells and B cells 4. Suppressor T cells (also called Ts cells) -Inhibit function of T cells and B cells |
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Explain Antigen Presentation.
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-T cells only recognize antigens that are bound to glycoproteins in plasma membranes
-MHC Proteins -The major histocompatibility complex (MHC) |
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What are the 2 classes of MHC Proteins?
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-Class I
-Found in membranes of all nucleated cells -Class II -Found in membranes of antigen-presenting cells (APCs) -Found in lymphocytes |
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What are Phagocytic APCs?
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1. Free and fixed macrophages
-In connective tissues 2. Kupffer cells -Of the liver 3. Microglia -In the CNS |
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What are Non-phagocytic APCs
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-Langerhans cells
-In the skin -Dendritic cells -In lymph nodes and spleen |
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What are CD Markers?
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-Also called cluster of differentiation markers
-In T cell membranes -Molecular mechanism of antigen recognition -More than 70 types -Designated by an identifying number CD3 Receptor Complex -Found in all T cells |
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Two Important CD Markers
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1. CD8 Markers
-Found on cytotoxic T cells and suppressor T cells -Respond to antigens on Class I MHC proteins 2. CD4 Markers -Found on helper T cells -Respond to antigens on Class II MHC proteins CD8 or CD4 Markers -Bind to CD3 receptor complex -Prepare cell for activation |
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Explain how CD8 T cells are activated
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-Activated by exposure to antigens on MHC proteins
-One responds quickly -Producing cytotoxic T cells and memory T cells -The other responds slowly -Producing suppressor T cells |
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What are Cytotoxic T Cells and what 3 things do they do?
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-Seek out and immediately destroy target cells
1. Release perforin -To destroy antigenic plasma membrane 2. Secrete poisonous lymphotoxin -To destroy target cell 3. Activate genes in target cell -That cause cells to die |
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Explain the steps of Antigen Recognition by and Activation of Cytotoxic T Cells
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1. Antigen recognition occurs when a CD8 T cell encounters an appropriate antigen on the surface of another cell, bound to a Class I MHC protein.
2. Costimulation activates CD8 T cell, Before activation can occur, a T cell must be chemically or physically stimulated by the abnormal target cell. 3. Activation and Cell Division (Antigen regognition results in T cell activation and cell division, producing active Tc cells and memory Tc cells. 4. The active Tc cell destroys the antigen-bearing cell. It may use several different mechanisms to kill target cell. This causes perforin, lymphotoxin, and cytokinine release, which respectively stimulate destruction of the plasma membrane, disruption of cell metabolism, and stimulation of apoptosis. |
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What are Memory Tc Cells
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-Produced with cytotoxic T cells
-Stay in circulation -Immediately form cytotoxic T cells if same antigen appears again |
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What are Suppressors T Cells
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-Secrete suppression factors
-Inhibit responses of T and B cells -Act after initial immune response -Limit immune reaction to single stimulus |
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How are CD4 T cells activated?
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Activation of CD4 T cells
Active helper T cells (Th cells) -Secrete cytokines Memory helper (Th) cells Remain in reserve |
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What are B Cells doing?
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-Responsible for antibody-mediated immunity
-Attack antigens by producing specific antibodies -Millions of populations, each with different antibody molecules |
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Explain B Cell Sensitization?
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-Corresponding antigens in interstitial fluids bind to B cell receptors
-B cell prepares for activation -Preparation process is sensitization -During sensitization, antigens are: -Taken into the B cell -Processed -Reappear on surface, bound to Class II MHC protein |
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What are Helper T Cells?
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-Sensitized B cell is prepared for activation but needs helper T cell activated by same antigen
B Cell Activation -Helper T cell binds to MHC complex -Secretes cytokines that promote B cell activation and division |
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Explain B Cell Division
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-Activated B cell divides into:
-Plasma cells -Memory B cells |
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What are Plasma Cells and what do Memory B Cells do?
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Plasma Cells
-Synthesize and secrete antibodies into interstitial fluid Memory B Cells -Like memory T cells, remain in reserve to respond to next infection |
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What are the combined responses to Viral Infection?
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Combined Responses to Viral Infection
-Similar to bacterial infection -But cytotoxic T cells and NK cells are activated by contact with virus-infected cells. |
