Immunology I Quiz
61 Questions
3 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of phagocytosis?

  • To induce vascular permeability and inflammation
  • To produce cytokines and activate immune responses
  • To capture and ingest foreign objects/microorganisms (correct)
  • To present antigens to the adaptive immune system

    • Which cell type predominate during acute inflammation?

  • Lymphocytes
  • Mast cells
  • Neutrophils (correct)
  • Monocytes/Macrophages

    • What is the purpose of vasodilation during inflammation?

  • To reduce leukocyte migration
  • To reduce blood flow to the affected area
  • To increase vascular permeability
  • To increase blood flow to the affected area (correct)

    • What is the role of chemokines in inflammation?

    <p>To guide leukocytes to follow a gradient of concentration</p> Signup and view all the answers

    What is the final step in the phagocytosis process?

    <p>Phagosome fusion with the lysosome</p> Signup and view all the answers

    Which immune system is engaged when lymphocytes are present?

    <p>Adaptive immunity</p> Signup and view all the answers

    What is the role of histamine in inflammation?

    <p>To increase vascular permeability</p> Signup and view all the answers

    What is the result of phagolysosome formation?

    <p>Destruction of microorganisms and damaged cells</p> Signup and view all the answers

    What is the purpose of serotonin in inflammation?

    <p>To increase vascular permeability</p> Signup and view all the answers

    Which step in phagocytosis involves the engulfment of the object through endocytosis?

    <p>Surrounding the captured object with pseudopodia</p> Signup and view all the answers

    What is the primary function of immune system?

    <p>To discriminate foreign elements from components of its own organism</p> Signup and view all the answers

    What is the role of dendritic cells in the immune system?

    <p>To present antigens to T-cells</p> Signup and view all the answers

    What is the function of neutrophils in innate immunity?

    <p>To phagocytose and eliminate pathogens</p> Signup and view all the answers

    What is the difference between innate and adaptive immunity?

    <p>Innate immunity is non-specific, while adaptive immunity is specific</p> Signup and view all the answers

    What is the role of cytokines in the immune system?

    <p>To communicate between immune cells</p> Signup and view all the answers

    What is the function of pattern recognition receptors (PRRs)?

    <p>To recognize pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs)</p> Signup and view all the answers

    What is the role of mast cells in the immune system?

    <p>To mediate allergic responses</p> Signup and view all the answers

    What is the difference between PAMPs and DAMPs?

    <p>PAMPs are found in microbes, while DAMPs are found in host cells</p> Signup and view all the answers

    What is the role of natural killer (NK) cells in the immune system?

    <p>To recognize and eliminate abnormal host cells</p> Signup and view all the answers

    What is the function of inflammation in the immune system?

    <p>To coordinate the immune response to tissue damage</p> Signup and view all the answers

    What is the primary mechanism of intracellular killing in phagocytosis?

    <p>Non-oxidative pathway</p> Signup and view all the answers

    What is the function of lactoferrin in phagocytosis?

    <p>Sequestrates iron to inhibit bacterial growth</p> Signup and view all the answers

    Which pathway is activated by antibodies binding to microbes or antigens?

    <p>Classical pathway</p> Signup and view all the answers

    What is the result of the action of the Membrane Attack Complex (MAC)?

    <p>Destruction by osmotic lysis</p> Signup and view all the answers

    What is the function of cationic proteins in phagocytosis?

    <p>Damages bacterial cell wall</p> Signup and view all the answers

    Which cells are responsible for recognizing and killing infected cells or cancer cells?

    <p>NK cells</p> Signup and view all the answers

    What is the primary mechanism of intracellular killing in the oxidative pathway?

    <p>Reactive oxygen species (ROS)</p> Signup and view all the answers

    What is the function of lysozyme in phagocytosis?

    <p>Damages mucopeptides in bacterial cell wall</p> Signup and view all the answers

    Which pathway is activated when a carbohydrate-binding plasma protein binds to terminal mannose residues on the surface glycoproteins?

    <p>Lectin pathway</p> Signup and view all the answers

    What is the primary function of the complement system?

    <p>Marking microorganisms for destruction</p> Signup and view all the answers

    Put correct steps in order for Phagocytosis ( at least 1-4 as no option for the last option)

    <p>First = Phagocytes detect and bind their target Second = Surround the captured object with pseudopodia and engulf the object through endocytosis Third = The endocytosed object becomes enclosed in the phagosome Fourth = Phagosome fuses with the lysosome to form a phagolysosome</p> Signup and view all the answers

    What is the primary function of antigen presentation in adaptive immunity?

    <p>To present peptides to T cells</p> Signup and view all the answers

    What is the function of MHC I molecules?

    <p>To present antigens to CD8+ T cells</p> Signup and view all the answers

    What is the primary function of Class II MHC molecules?

    <p>To present antigens to CD4+ T cells</p> Signup and view all the answers

    What is the requirement for antigen presentation through MHC I molecules?

    <p>Antigens must be from the cytosol of the cell</p> Signup and view all the answers

    Which type of cells present antigens to CD4+ T cells?

    <p>Dendritic cells</p> Signup and view all the answers

    What is the primary function of CD4+ Th1 cells?

    <p>Activation of macrophages</p> Signup and view all the answers

    Which cells are responsible for presenting antigens to T cells through MHC II molecules?

    <p>Dendritic cells</p> Signup and view all the answers

    What is the role of T cells in adaptive immunity?

    <p>To recognize and respond to antigens</p> Signup and view all the answers

    What happens to immature DCs when they encounter antigens in tissues?

    <p>They migrate to lymphoid tissue</p> Signup and view all the answers

    What is the primary function of B cells in adaptive immunity?

    <p>To produce immunoglobulins</p> Signup and view all the answers

    What is the function of CD8+ CTLs?

    <p>Killing of infected cells</p> Signup and view all the answers

    What is the result of antigen presentation by mature DCs?

    <p>Activation of CD4+ T cells</p> Signup and view all the answers

    What is the role of antigen receptors in adaptive immunity?

    <p>To recognize pathogenic epitopes</p> Signup and view all the answers

    What is the primary function of CD8+ T cells?

    <p>To recognize and respond to antigens</p> Signup and view all the answers

    What is the role of cytokines in CD4+ T cell differentiation?

    <p>Differentiation into different T cell subsets</p> Signup and view all the answers

    What is the function of MHC molecules in adaptive immunity?

    <p>To present peptides to T cells</p> Signup and view all the answers

    What happens to activated CD4+ T cells?

    <p>They differentiate into effector cells and memory cells</p> Signup and view all the answers

    Which cells are responsible for presenting antigens to CD4+ T cells in lymph nodes?

    <p>Dendritic cells</p> Signup and view all the answers

    What is the primary function of CD4+ Th2 cells?

    <p>Antibody production</p> Signup and view all the answers

    What happens to immature DCs after they migrate to lymphoid tissue?

    <p>They mature</p> Signup and view all the answers

    Which of the following is NOT a characteristic of T-independent activation of B cells?

    <p>Activated by Th cells</p> Signup and view all the answers

    Which immunoglobulin isotype is primarily found in mucous membranes?

    <p>IgA</p> Signup and view all the answers

    What is the primary function of IgG in the humoral response?

    <p>Providing secondary immune response</p> Signup and view all the answers

    Which of the following is a characteristic of IgM?

    <p>Is the first antibody to respond to an infection</p> Signup and view all the answers

    What is the primary function of IgE in the humoral response?

    <p>Mediating allergic reactions</p> Signup and view all the answers

    Which of the following is a characteristic of T-dependent activation of B cells?

    <p>Activated by Th cells</p> Signup and view all the answers

    What is the primary function of IgD in the humoral response?

    <p>Antigen recognition on the surface of B cells</p> Signup and view all the answers

    Which of the following is a characteristic of IgA in the humoral response?

    <p>Is involved in mucosal immunity</p> Signup and view all the answers

    Which of the following is NOT a characteristic of IgM?

    <p>Is involved in secondary immune responses</p> Signup and view all the answers

    What is the primary function of IgG in the distribution of immunoglobulin isotypes?

    <p>Found in blood and tissues</p> Signup and view all the answers

    Study Notes

    Immune System

    • The immune system is a collection of cells, tissues, and molecules that mediate resistance to foreign elements (antigens).
    • Immune response is a coordinated reaction of cells and molecules to antigens.

    Antigens and Epitopes

    • Antigens are molecules that induce an immune response when introduced into the body.
    • Epitopes or antigenic determinants are parts of an antigen that induce the immune response and bind to lymphocyte receptors and antibodies.

    Self vs Non-Self

    • The immune system must be able to discriminate between foreign elements and components of its own organism to prevent autoimmunity.
    • Immune responses should be generated only when components of the immune system come into contact with non-self elements.

    Innate and Adaptive Immunity

    • There are two types of defense: Innate Immunity (non-specific) and Adaptive Immunity (specific).
    • Innate Immunity is always active, whereas Adaptive Immunity is activated only when in contact with antigens.

    Cells of the Immune System

    • Neutrophils:
      • Role: Antimicrobial effectors, particularly in acute bacterial infection/inflammation
      • Mechanism: Phagocytosis; degranulation; neutrophil extracellular trap formation
    • Eosinophils:
      • Role: Antiparasitic effectors, particularly in helminthic infection; some antiviral action
      • Mechanism: degranulation; limited phagocytosis
    • Basophils:
      • Role: Mediator of inflammation
      • Mechanism: degranulation
    • Mast cells:
      • Role: Immune surveillance, mediator and amplifier of inflammation and allergy
      • Mechanism: detection of threats and release of inflammatory mediators via degranulation or synthesis of lipid mediators and cytokines
    • Macrophages:
      • Role: Immune surveillance, moderate antimicrobial capacity, limited antigen presentation
      • Mechanism: detection of threats and release of inflammatory mediators; phagocytosis
    • Dendritic cells:
      • Role: Immune surveillance, antigen processing, and presentation
      • Mechanism: detection of threats and release of inflammatory mediators; endocytosis and phagocytosis
    • Lymphocytes:
      • NK cells:
        • Role: Destruction of virally infected or abnormal host cells (including tumor cells)
        • Mechanism: recognition of virally infected or abnormal host cells and targeted release of cytotoxic granules
      • T cells and B cells:
        • Role: adaptive immunity; recognition of specific antigens/epitopes
        • Mechanism: activation and regulation of cell-mediated and antibody responses; memory cells

    Cell Communication in the Immune System

    • Cell-to-cell contact:
      • Receptors: expressed on the surface of a cell or in intracellular compartments
      • Ligands: molecules that activate receptors, can be soluble or membrane-bound
    • Cytokines:
      • Proteins with diverse functions, such as cell growth, activation, and communication between cells
      • Examples: interleukins, chemokines

    Innate Immunity

    • Recognition of Pathogens:
      • Pathogen-Associated Molecular Patterns (PAMPs): recognizable by the innate immune system
      • Pattern Recognition Receptors (PRRs): receptors of innate immunity that recognize PAMPs
    • Recognition of Damage:
      • Damage-Associated Molecular Patterns (DAMPs): released when cells die or connective tissue is damaged
    • Sentinel Cells:
      • Recognition of threats: PAMPs and DAMPs
      • Examples: dendritic cells, macrophages, and mast cells
    • Inflammation:
      • Sentinel cells exposed to PAMPs, DAMPs, or pro-inflammatory cytokines
      • Cell activation: upregulation of cellular antimicrobial defenses and release of pro-inflammatory mediators
    • Phagocytosis:
      • Active process of capturing and ingesting foreign objects/microorganisms by phagocytes
      • Destruction of microorganisms, damaged cells, and cellular debris
      • Induction of cytokine production and processing and presentation of antigens
    • Complement System:
      • Collection of circulating and membrane-associated proteins
      • Activation occurs in a sequential manner through three pathways: alternative, classical, and lectin
      • Leads to the formation of the Membrane Attack Complex (MAC), which breaches the cell membrane of the microbe, leading to destruction by osmotic lysis
    • NK cells:
      • Destruction of virally infected or abnormal host cells (including tumor cells)
      • Mechanism: recognition of virally infected or abnormal host cells and targeted release of cytotoxic granules

    Objectives

    • Understand the mechanisms of adaptive immunity

    Antigen Presentation

    • Antigen receptors on T cells and B cells recognize who introduced the antigen
    • Antigen presentation is required for activation of T cells
    • T cells recognize pathogenic epitopes

    Antigen Processing & Presentation

    • Major Histocompatibility Complex (MHC) molecules present antigens to T cells
    • Class I MHC presents antigens to CD8+ T cells
    • Class I MHC takes any protein, breaks it down, and presents it on the cell surface
    • Class II MHC presents antigens to CD4+ T cells
    • Professional antigen-presenting cells (APCs) present antigens on MHC II molecules

    Activation of Naive T cells

    • Naive T cells require a level of stimulation to be activated by dendritic cells
    • Activation always done by a dendritic cell
    • Proliferation and differentiation of activated T cells into effector and memory T cells

    Immature Dendritic Cells

    • Encounter antigens in tissues
    • Migrate to lymphoid tissue and mature
    • Present antigens to T cells in lymph nodes

    Differentiation of Activated T cells

    • T cell subsets: CD4+ and CD8+
    • CD4+ T cells: Th1, Th2, Th17 differ due to cytokines
    • CD4+ T cells express surface molecules and secrete cytokines that activate other cells
    • CD8+ T cells: Cytotoxic T Lymphocytes (CTLs) that kill infected cells

    Adaptive Immunity - Cellular Response

    • CD4+ Th1 cells: secrete cytokines, activate macrophages, and activate CD8+ CTLs
    • CD8+ CTLs: induce apoptosis of infected cells

    Adaptive Immunity - Humoral Response

    • B cells recognize antigens without MHC presentation
    • B cells are activated by Th cells (T-dependent) or polysaccharides (T-independent)
    • Immunoglobulins (Ig): isotypes or classes include IgG, IgM, IgA, IgE, and IgD

    Immunoglobulins

    • Basic structure: two heavy chains and two light chains
    • Isotypes differ in heavy chain structure, monomeric vs polymeric, subclasses, serum concentration, half-life, and functions

    Distribution of Ig Isotypes

    • IgM: found in blood
    • IgG: found in blood and tissues
    • IgA: found in mucous membranes
    • IgE: found in epithelial tissue

    Primary and Secondary Responses

    • IgM: major Ab of primary responses
    • IgG: major Ab of secondary responses

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Immunology I - Ross University - PDF
    Immunology II Course Notes PDF

    Description

    Test your knowledge of immune response, immune system components, and mechanisms of innate immunity, including inflammation, phagocytosis, and complement systems.

    More Like This

    Immunology: Innate Immune Response
    140 questions

    Immunology: Innate Immune Response

    StimulatingPipeOrgan avatar
    StimulatingPipeOrgan
    Innate Immunology Quiz
    9 questions

    Innate Immunology Quiz

    ValuableHeliotrope5203 avatar
    ValuableHeliotrope5203
    Immunology: Innate Immune Response Overview
    56 questions

    Immunology: Innate Immune Response Overview

    HumaneOcean avatar
    HumaneOcean
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser