Podcast
Podcast
Podcast
Something went wrong
Questions and Answers
Questions and Answers
What is the primary function of the complement system in the innate immune response?
What is the primary function of the complement system in the innate immune response?
- To amplify the humoral response (correct)
- To produce antibodies
- To generate cytokines
- To directly kill pathogens
Which of the following describes a mechanism by which complement activation assists in pathogen elimination?
Which of the following describes a mechanism by which complement activation assists in pathogen elimination?
- Induces cell apoptosis
- Causes opsonization of antigens (correct)
- Inhibits phagocytosis
- Promotes the growth of pathogens
What is the role of C3b in the immune response?
What is the role of C3b in the immune response?
- Facilitates the clearance of immune complexes (correct)
- Inhibits immune complex formation
- Stimulates antibody production
- Directly lyses bacteria
How does the complement system contribute to inflammation?
How does the complement system contribute to inflammation?
Why are Gram+ bacteria generally more resistant to MAC-mediated lysis?
Why are Gram+ bacteria generally more resistant to MAC-mediated lysis?
What mechanism facilitates the viral neutralization process involving the complement system?
What mechanism facilitates the viral neutralization process involving the complement system?
What happens if there are deficiencies in complement components?
What happens if there are deficiencies in complement components?
Complement effector mechanisms primarily utilize which of the following?
Complement effector mechanisms primarily utilize which of the following?
Questions and Answers
Something went wrong
Flashcards
Flashcards
What is the role of the complement system in the innate immune response?
What is the role of the complement system in the innate immune response?
The complement system is a part of the innate immune response that uses a cascade of proteins to eliminate pathogens.
How does complement activation eliminate pathogens?
How does complement activation eliminate pathogens?
Complement activation leads to pathogen elimination via several mechanisms: lysis of cells, inflammation, opsonization, and clearance of immune complexes.
How does the complement system lyse cells?
How does the complement system lyse cells?
The Membrane Attack Complex (MAC) forms a pore in the cell membrane, leading to cell lysis. This is effective against a wide range of cells, including bacteria, but some bacteria have developed mechanisms to evade MAC.
How does the complement system mediate inflammation?
How does the complement system mediate inflammation?
Signup and view all the flashcards
What is opsonization?
What is opsonization?
Signup and view all the flashcards
How does the complement system neutralize viruses?
How does the complement system neutralize viruses?
Signup and view all the flashcards
How does the complement system clear immune complexes?
How does the complement system clear immune complexes?
Signup and view all the flashcards
What are complement receptors and what is their role?
What are complement receptors and what is their role?
Signup and view all the flashcards
Flashcards
Something went wrong
Study Notes
Study Notes
Complement System: Biological Consequences
- The complement system plays a crucial role in the innate immune response.
- Complement activation leads to pathogen elimination through various mechanisms.
Biological Consequences of Complement Activation
- Amplifies humoral response: Complement enhances the effectiveness of antibody-mediated defenses.
- Lyses cells: The membrane attack complex (MAC) directly destroys pathogen cell membranes.
- Inflammatory response: Complement components trigger inflammation, attracting immune cells to the site of infection.
- Opsonisation: Complement proteins (e.g., C3b, C4b) coat pathogens, making them more readily recognized and engulfed by phagocytic cells.
- Clearance of immune complexes: Complement helps remove immune complexes from circulation to prevent tissue damage.
Cell Lysis
- MAC targets a broad spectrum of cells: The MAC is effective against a wide range of pathogens involved in infections.
- Gram-positive bacteria resistance: Gram-positive bacteria often have thicker cell walls (peptidoglycan), offering protection against MAC formation.
- Evasion mechanisms: Certain pathogens have evolved strategies to evade complement-mediated killing.
Microbial Evasion of Complement-Mediated Damage
- Some pathogens have mechanisms to obstruct the complement cascade, such as altering the composition of their cell walls to prevent MAC insertion or producing enzymes that inactivate complement components.
- Details of mechanisms by which specific pathogens can limit complement activation are listed.
Mediating Inflammation
- Anaphylatoxins: Complement components (e.g., C3a, C5a) activate mast cells and basophils, resulting in inflammation.
- Vascular permeability: Complement activation enhances the permeability of blood vessels to allow immune cells to enter the infected tissue.
- Chemotaxis: Complement components attract immune cells to the site of infection.
Opsonisation
- C3b and C4b mediate phagocytosis: These complement components act as opsonins, enhancing phagocytosis by macrophages and neutrophils.
- Phagocytosis is a critical process of removing pathogens to limit infection and inflammation.
Viral Neutralization
- Complement activation can neutralize viruses by interfering with their ability to infect cells.
- The mechanisms range from binding to viral surfaces to lysing virus-infected cells.
- This helps prevent the spread of viral infections and reduce the potential for viral replication.
Clearing of Immune Complexes
- Immune complex buildup: Accumulation of immune complexes can trigger tissue damage.
- C3b coating of complexes: C3b coats harmful immune complexes.
- Removal by RBCs: Red blood cells assist in transporting and removing immune complexes to prevent harm.
- Liver and spleen clearance: The liver and spleen filter and remove immune complexes from the blood.
- Complement deficiency: Deficiencies in complement proteins can impair the clearance of immune complexes, potentially leading to complications.
Complement Receptors
- Complement receptors mediate complement effector mechanisms: These receptors on immune cells recognize and bind to complement-coated pathogens.
- Types of receptors are identified and their specific roles are described.
Summary
- The activated complement system significantly boosts the immune response.
- Direct cell death occurs by forming a MAC.
- Inflammation is induced to attract immune cells to infection sites.
- These mechanisms collectively strengthen the immune system's ability to eliminate pathogens and maintain homeostasis.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Study Notes
Something went wrong
