Podcast
Questions and Answers
Which component is not part of the innate immunity?
Which component is not part of the innate immunity?
What is the primary function of the spleen in the immune system?
What is the primary function of the spleen in the immune system?
Which statement about adaptive immunity is true?
Which statement about adaptive immunity is true?
Where are T-cells matured?
Where are T-cells matured?
Signup and view all the answers
What kind of immunity do macrophages contribute to?
What kind of immunity do macrophages contribute to?
Signup and view all the answers
Which lymphoid tissue is responsible for localized immune defense?
Which lymphoid tissue is responsible for localized immune defense?
Signup and view all the answers
Which statement describes a characteristic of innate immunity?
Which statement describes a characteristic of innate immunity?
Signup and view all the answers
What is the role of antigen presenting cells in the immune system?
What is the role of antigen presenting cells in the immune system?
Signup and view all the answers
Which types of cells primarily interact with antigenic epitopes using their immunoglobulin receptors?
Which types of cells primarily interact with antigenic epitopes using their immunoglobulin receptors?
Signup and view all the answers
What is a primary function of CD8 Cytotoxic T-lymphocytes (CTLs)?
What is a primary function of CD8 Cytotoxic T-lymphocytes (CTLs)?
Signup and view all the answers
What do immature B cells exclusively express on their surface?
What do immature B cells exclusively express on their surface?
Signup and view all the answers
What role do Plasma cells play in the immune response?
What role do Plasma cells play in the immune response?
Signup and view all the answers
How do B cells mark pathogens for destruction?
How do B cells mark pathogens for destruction?
Signup and view all the answers
Which statement accurately describes the function of Natural Killer (NK) cells?
Which statement accurately describes the function of Natural Killer (NK) cells?
Signup and view all the answers
What is the significance of clonal expansion in B cells?
What is the significance of clonal expansion in B cells?
Signup and view all the answers
Which type of immune cell is primarily responsible for the immediate, non-specific response to pathogens?
Which type of immune cell is primarily responsible for the immediate, non-specific response to pathogens?
Signup and view all the answers
How do mature B cells differ from immature B cells?
How do mature B cells differ from immature B cells?
Signup and view all the answers
Which immune cells are known for producing antibodies?
Which immune cells are known for producing antibodies?
Signup and view all the answers
What is the main function of dendritic cells in the immune system?
What is the main function of dendritic cells in the immune system?
Signup and view all the answers
How do cytotoxic T cells carry out their function?
How do cytotoxic T cells carry out their function?
Signup and view all the answers
Which of the following cells suppress immune responses to maintain tolerance?
Which of the following cells suppress immune responses to maintain tolerance?
Signup and view all the answers
Monocytes are best described as what in relation to macrophages?
Monocytes are best described as what in relation to macrophages?
Signup and view all the answers
Which immune cells migrate to lymph nodes after capturing antigens?
Which immune cells migrate to lymph nodes after capturing antigens?
Signup and view all the answers
Which of these is NOT an innate immune cell?
Which of these is NOT an innate immune cell?
Signup and view all the answers
Which cell types are considered antigen-presenting cells (APCs)?
Which cell types are considered antigen-presenting cells (APCs)?
Signup and view all the answers
What is the primary function of effector cells in the immune response?
What is the primary function of effector cells in the immune response?
Signup and view all the answers
Which lymphocyte type is primarily responsible for cell-mediated immunity?
Which lymphocyte type is primarily responsible for cell-mediated immunity?
Signup and view all the answers
Which of the following describes the role of CD4+ T helper cells?
Which of the following describes the role of CD4+ T helper cells?
Signup and view all the answers
What occurs in the outer cortex of the thymus during T-lymphocyte development?
What occurs in the outer cortex of the thymus during T-lymphocyte development?
Signup and view all the answers
Which cytokines are primarily produced by Th1 cells?
Which cytokines are primarily produced by Th1 cells?
Signup and view all the answers
How are T lymphocytes classified in the CD nomenclature?
How are T lymphocytes classified in the CD nomenclature?
Signup and view all the answers
Which option correctly identifies a subset of T helper cells and their primary function?
Which option correctly identifies a subset of T helper cells and their primary function?
Signup and view all the answers
Study Notes
Immune System Overview
- The immune system is a complex network of tissues, cells and molecules.
- It defends the body against infections, foreign substances and abnormal cells (like cancer).
Learning Objectives
- Define the immune system
- Identify and list the cells of the immune system
- Know the function of B and T lymphocytes
Immune System Tissues
-
Primary Lymphoid Organs
- Bone Marrow: Site of hematopoiesis (blood cell production); produces B cells (mature in bone marrow) and immature T cells.
- Thymus: Site where T cells mature and undergo selection to become functional.
-
Secondary Lymphoid Organs
- Lymph Nodes: Filter lymphatic fluid, house immune cells to detect and respond to antigens.
- Spleen: Filters blood, removes pathogens, old red blood cells and debris; contains white pulp (immune function) and red pulp cells.
- Mucosa-Associated Lymphoid Tissue (MALT): Provides localized immune defense at mucosal surfaces (e.g., tonsils, Peyer's patches, appendix).
- Skin-Associated Lymphoid Tissue (SALT): Immune components in the skin protect against pathogens breaching the skin barrier.
Cells of the Immune System
-
Innate Immune Cells (Immediate, Non-specific Response):
- Neutrophils: Rapid responders that engulf and destroy bacteria and fungi.
- Macrophages: Large phagocytes engulfing pathogens and dead cells, presenting antigens to T cells.
- Dendritic Cells: Professional antigen-presenting cells linking innate and adaptive systems.
- Natural Killer (NK) Cells: Destroy virus-infected and abnormal cells through apoptosis.
- Mast Cells: Release histamine and other chemicals during allergic responses and inflammation.
- Eosinophils: Involved in combating parasitic infections and allergic reactions.
- Basophils: Release inflammatory mediators and play a role in allergies.
-
Adaptive Immune Cells (Specific, Slower Response, with Memory):
- B Lymphocytes (B Cells): Produce antibodies to neutralize pathogens; differentiate into plasma cells (antibody-producing cells) and memory B cells.
- T Lymphocytes (T Cells):
- Helper T cells (CD4+): Activate other immune cells (including B cells and cytotoxic T cells).
- Cytotoxic T cells (CD8+): Kill virus-infected and cancerous cells.
- Regulatory T cells: Suppress immune responses to maintain tolerance and prevent autoimmunity.
- Memory T cells: Long-lived cells providing faster responses upon re-exposure to antigens.
-
Other Immune Cells:
- Monocytes: Precursors to macrophages and dendritic cells, circulating in the blood.
- Platelets: Involved in blood clotting and release immune mediators during inflammation.
-
Antigen-Presenting Cells (APCs): Specialized cells processing and presenting antigens to T cells, initiating adaptive immune responses. Examples include dendritic cells and macrophages.
T Lymphocytes
- 80% of circulating lymphocytes
- Cytotoxic T cells (CD8): Attack foreign cells or body cells infected by viruses (cell-mediated immunity).
- Regulatory T cells (CD4): Helper T cells and suppressor T cells control activation and activity of B cells.
CD Nomenclature
- The CD nomenclature is a standardized system to classify and identify molecules on the surface of immune cells, including lymphocytes.
- CD molecules are used to classify leukocytes into functionally distinct groups (e.g., helper T cells).
- CD molecules are often involved in leukocyte functions.
B Lymphocytes
- B lymphocytes are formed in the bone marrow and develop there. They interact with antigenic epitopes using immunoglobulin receptors. Development into plasma cells secrete specific antibodies.
- Immature B cells express IgM receptors. Mature B cells express IgM and IgD molecules as antigen receptors.
- B cells have receptors for the Fc portion of IgG and a receptor for the C3 component of the complement.
Natural Killer (NK) Cells
- 5-10% of circulating lymphocytes
- Attack foreign cells, normal cells infected with viruses, and cancer cells.
- Known as "immunologic surveillance."
Antibody Structure
- Antibodies are composed of two identical heavy chains and two identical light chains. Specific antigen-binding sites on antibodies recognize pathogens, binding to them and marking them for destruction by complement activation or phagocytes.
Other details in the slides:
- Th1 & Th2 Subsets: Different types of helper T cells (Th1 and Th2) produce different cytokines.
- CD8 Cytotoxic T-lymphocytes: Constitute 35% of peripheral T cells; Recognize antigens on target cells (infected cells or tumor cells) in association with MHC proteins. Activate and kill virus-infected cells or tumor cells.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz covers the basics of the immune system, including its definition, functions, and the cells involved. You'll learn about primary and secondary lymphoid organs and their respective roles in immune defense. Understand how B and T lymphocytes contribute to the body's response to infections.
