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Questions and Answers
What are pathogens?
What are pathogens?
Immunity refers to vulnerability to damage or disease.
Immunity refers to vulnerability to damage or disease.
False
Name the primary organ system that defends the body against disease.
Name the primary organ system that defends the body against disease.
lymphatic system
Lymph is richer in dietary __________ as it exits the GI tract.
Lymph is richer in dietary __________ as it exits the GI tract.
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Match the following functions to the lymphatic system:
Match the following functions to the lymphatic system:
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What is the primary function of lymphatic capillaries?
What is the primary function of lymphatic capillaries?
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Lymphatic vessels only drain lymph from the lower body.
Lymphatic vessels only drain lymph from the lower body.
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What do we call the fluid collected in lipid-rich lymph?
What do we call the fluid collected in lipid-rich lymph?
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The main lymphatic duct draining the majority of the body is the _____.
The main lymphatic duct draining the majority of the body is the _____.
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Match the lymphatic organs with their functions:
Match the lymphatic organs with their functions:
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Which lymphatic vessel is not universally present in all individuals?
Which lymphatic vessel is not universally present in all individuals?
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Endothelial cell edges of lymphatic capillaries do not allow interstitial fluid to exit.
Endothelial cell edges of lymphatic capillaries do not allow interstitial fluid to exit.
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What is the role of skeletal muscle and respiratory pumps in the lymphatic system?
What is the role of skeletal muscle and respiratory pumps in the lymphatic system?
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Approximately _____% of fluid is returned to circulation via the lymphatic system.
Approximately _____% of fluid is returned to circulation via the lymphatic system.
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What structure absorbs dietary lipids from digestion?
What structure absorbs dietary lipids from digestion?
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What type of immunity is generated from vaccines?
What type of immunity is generated from vaccines?
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Self-tolerance in adaptive immunity allows the immune system to react to self-antigens.
Self-tolerance in adaptive immunity allows the immune system to react to self-antigens.
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What is the primary immune response stimulated by vaccines?
What is the primary immune response stimulated by vaccines?
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The measles virus can cause immunological ___________ .
The measles virus can cause immunological ___________ .
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What happens to T cells that do not bind MHC-I during development?
What happens to T cells that do not bind MHC-I during development?
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Individuals with HIV are especially susceptible to infections because the virus preferentially infects ___________ cells.
Individuals with HIV are especially susceptible to infections because the virus preferentially infects ___________ cells.
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Match the immune system concepts with their descriptions:
Match the immune system concepts with their descriptions:
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What is a common example of hypersensitivity in the immune system?
What is a common example of hypersensitivity in the immune system?
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Anaphylaxis is a systemic inflammatory response that can occur from a second exposure to an allergen.
Anaphylaxis is a systemic inflammatory response that can occur from a second exposure to an allergen.
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What is the primary reason for the inability of untreated individuals with HIV to mount adaptive immune responses?
What is the primary reason for the inability of untreated individuals with HIV to mount adaptive immune responses?
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Which of the following cells are formed in multipotent stem cells?
Which of the following cells are formed in multipotent stem cells?
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The thymus gland increases in size as a person ages.
The thymus gland increases in size as a person ages.
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What type of lymphocytes become immunocompetent in the thymus?
What type of lymphocytes become immunocompetent in the thymus?
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The spleen is located in the left __________ region of the abdomen.
The spleen is located in the left __________ region of the abdomen.
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Match the following lymphatic organs with their primary function:
Match the following lymphatic organs with their primary function:
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Which component of the immune system is the first line of defense?
Which component of the immune system is the first line of defense?
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Cilia in the respiratory tract help trap and sweep harmful particles away.
Cilia in the respiratory tract help trap and sweep harmful particles away.
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Name one antimicrobial substance produced by the body.
Name one antimicrobial substance produced by the body.
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The __________ pulp in the spleen contains lymphocytes and macrophages.
The __________ pulp in the spleen contains lymphocytes and macrophages.
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Match the following immune cells with their functions:
Match the following immune cells with their functions:
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What is the role of interferons in the immune response?
What is the role of interferons in the immune response?
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Phagocytes are responsible for engulfing and destroying other cells or large particles.
Phagocytes are responsible for engulfing and destroying other cells or large particles.
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What is the function of the red pulp in the spleen?
What is the function of the red pulp in the spleen?
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The external defenses of innate immunity include __________ membranes.
The external defenses of innate immunity include __________ membranes.
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What is the role of pseudopods in phagocytosis?
What is the role of pseudopods in phagocytosis?
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Histamine reduces blood flow to the site of injury.
Histamine reduces blood flow to the site of injury.
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What structure forms when a phagosome fuses with a lysosome?
What structure forms when a phagosome fuses with a lysosome?
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The immune response that occurs regardless of the type of pathogen is called __________.
The immune response that occurs regardless of the type of pathogen is called __________.
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Match the immune cells with their primary roles:
Match the immune cells with their primary roles:
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Which of the following proteins enhance leukocyte chemotaxis?
Which of the following proteins enhance leukocyte chemotaxis?
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Antibody-mediated immunity primarily defends against intracellular pathogens.
Antibody-mediated immunity primarily defends against intracellular pathogens.
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What happens to blood vessels during inflammation?
What happens to blood vessels during inflammation?
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Inflammation results in the signs and symptoms known as __________.
Inflammation results in the signs and symptoms known as __________.
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What is the function of CD4 proteins in T lymphocytes?
What is the function of CD4 proteins in T lymphocytes?
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All body cells express Class I MHC antigens except for erythrocytes.
All body cells express Class I MHC antigens except for erythrocytes.
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What are effector cells?
What are effector cells?
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Define chemotaxis in the context of the immune response.
Define chemotaxis in the context of the immune response.
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During tissue healing, __________ are proteins that promote vasodilation.
During tissue healing, __________ are proteins that promote vasodilation.
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Memory cells actively kill or attack invaders.
Memory cells actively kill or attack invaders.
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What type of antigens are exogenous antigens?
What type of antigens are exogenous antigens?
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Match the type of immunity with its characteristic:
Match the type of immunity with its characteristic:
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Activated T cells require __________ to fully activate.
Activated T cells require __________ to fully activate.
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Match the following cells with their primary function:
Match the following cells with their primary function:
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What role do CD8 proteins play in CTL activation?
What role do CD8 proteins play in CTL activation?
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Plasma cells and plasmocytes refer to the same type of cells.
Plasma cells and plasmocytes refer to the same type of cells.
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What is the primary role of antibodies?
What is the primary role of antibodies?
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The first exposure to an antigens leads to a __________ immune response.
The first exposure to an antigens leads to a __________ immune response.
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Match the following terms with their definitions:
Match the following terms with their definitions:
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Which type of antigen is presented on MHC-I molecules?
Which type of antigen is presented on MHC-I molecules?
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Helper T lymphocytes can activate B cells.
Helper T lymphocytes can activate B cells.
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What are the two populations of lymphocytes produced during clonal selection?
What are the two populations of lymphocytes produced during clonal selection?
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Antigen-presenting cells (APCs) include __________ and macrophages.
Antigen-presenting cells (APCs) include __________ and macrophages.
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Study Notes
Lymphatic System
- The lymphatic system is the main organ system for defending against diseases and damage.
- It consists of lymph, lymphatic vessels, and lymphatic organs.
- Lymph is similar in composition to interstitial fluid and blood but richer in lipids after exiting the GI tract.
- Lymph is filtered in lymphoid tissues and/or organs.
- Lymphatic vessels begin as capillaries between cells that permit interstitial fluid to enter but not exit.
- When interstitial fluid pressure is higher than inside the vessels, the fluid enters the lymphatic capillaries.
- Specialized lymphatic capillaries in the small intestine (lacteals) absorb dietary lipids, forming chyle (creamy white lymph).
- Lymphatic capillaries merge into lymphatic vessels, which carry lymph to lymph nodes and other lymphoid tissues for filtration.
- Lymphatic vessels merge into lymph trunks that empty into lymphatic ducts (right and thoracic).
- The right lymphatic duct drains lymph from the head, neck, and right upper limb into the right subclavian vein.
- The thoracic duct, the largest lymphatic vessel, begins at the cisterna chyli and empties into the left subclavian vein.
- The lymphatic system returns about 15% of filtered fluid (approximately 3 liters daily) to the circulatory system via skeletal muscle and respiratory pumps.
Lymphatic Organs and Tissues
- Lymphatic organs are grouped into primary and secondary types.
- Primary lymphatic organs are the red bone marrow and thymus.
- Red bone marrow contains stem cells that give rise to blood cells, including lymphocytes.
- The thymus is a bilobed gland where T lymphocytes mature.
- The thymus cortex contains epithelial cells that train immature T cells, while the medulla contains mature T cells.
- Secondary lymphatic organs include the spleen and lymph nodes, which contain immunocompetent cells.
- The spleen is the largest mass of lymphatic tissue, filtering blood and removing worn-out cells.
- Lymph nodes are bean-shaped organs that filter lymph and contain lymphoid nodules (clusters of B cells).
- Lymphatic tissues lack a capsule, found in mucous membranes and Peyer's patches (aggregated lymphoid follicles).
- Lymph nodes receive lymph via afferent vessels and release lymph through efferent vessels.
Immunity
- Immunity is the body's resistance to damage or disease. Susceptibility is vulnerability to disease.
- Pathogens are disease-causing microorganisms (bacteria, viruses, fungi, parasites).
- Immunity is broadly divided into innate and adaptive immunity.
- Innate immunity is nonspecific, fast, and found in all animals.
- Adaptive immunity is specific, slower, and only found in vertebrates.
Innate Immunity
- Innate immunity has external defenses (first line) and internal defenses (second line).
- External defenses include:
- Skin with keratin and acidic/salty environment.
- Mucous membranes with mucus, cilia, tears (with lysozyme), and other fluids.
- Antimicrobial substances (interferons, complement proteins, iron-binding proteins, AMPs).
- Internal defenses include phagocytes (neutrophils, macrophages).
- Phagocytosis process: chemotaxis, adherence, ingestion (phagosome formation), digestion (phagolysosome formation), and killing.
- Inflammation: a nonspecific response to tissue damage, characterized by redness, swelling, heat, pain, and immobility.
- Chemicals that cause inflammation: histamine, kinins, prostaglandins, leukotrienes, complement proteins.
- Fever is an innate immune response that raises body temperature to combat infection.
Adaptive Immunity
- Adaptive immunity uses lymphocytes (including cytotoxic t lymphocytes (CTLs) and helper t lymphocytes (HTLs)) with antigen receptors to recognize specific antigens.
- Lymphocytes are clonally selected and produce effector and memory cells for long-term protection.
- Antigens are processed and presented by antigen-presenting cells (APCs) to activate lymphocytes.
- Exogenous antigens are processed by APCs using MHC-II.
- Endogenous antigens are processed by APCs using MHC-I.
- T cell activation requires costimulation using cytokines.
- CTLs directly kill infected cells via perforins and granzymes.
- HTLs activate other lymphocytes (e.g., B cells), producing antibodies to fight extracellular pathogens.
- Antibodies are immunoglobulin proteins made by plasma cells, enhancing phagocytosis and promoting cell lysis.
Immunological Memory
- First exposure to an antigen results in a primary immune response with slower antibody production.
- Subsequent exposure to the same antigen triggers a faster and stronger secondary immune response due to memory lymphocytes.
- Vaccines use harmless antigens to stimulate the primary immune response and create immunological memory.
Self-Recognition and Self-Tolerance
- The immune system must distinguish between self and foreign cells.
- Positive selection in the thymus ensures T cells can recognize self-MHC molecules.
- Negative selection eliminates T cells that react to self-antigens to prevent autoimmunity.
- Failure of self-tolerance can lead to autoimmune disorders.
Homeostatic Imbalances
- Immunodeficiency diseases reduce immune system function.
- Autoimmune disorders mistakenly attack self-antigens.
- Hypersensitivities are excessive immune responses to harmless substances.
- AIDS results from HIV infection preferentially targeting CD4+ HTLs, reducing the adaptive immune response.
- Allergies are a type of hypersensitivity.
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Description
This quiz explores the components and functions of the lymphatic system. It covers aspects such as lymph composition, lymphatic vessels, and the role of lymph nodes in filtering lymph. Test your knowledge on this crucial organ system that protects against diseases.