Microbiology Chapter 17 Flashcards

Study Notes

Immunity Types

Innate Immunity: Non-specific defense mechanisms against any pathogen, including external and internal responses.
Adaptive Immunity: Specific resistance against particular pathogens, involving memory cells and antigens.

Immunity Responses

Humoral Immunity: Mediated by B cells, which produce antibodies and mature in bone marrow.
Cellular Immunity: Involves T cells, which respond to infected or abnormal cells and mature in the thymus.

Antigens and Antibodies

Antigen: Any substance triggering specific antibody production or sensitized T cell response.
Epitope: The smallest part of an antigen recognized by antibodies.
Hapten: Small molecules that become immunogenic when attached to a larger carrier, e.g., Penicillin.

Antibody Types

Antibody (Immunoglobulin): Proteins that bind to antigens to neutralize or eliminate pathogens.
IgG: Monomer that enhances phagocytosis, neutralizes toxins, and can cross the placenta.
IgM: Pentamer that agglutinates microbes and is the first antibody produced during infection.
IgA: Dimer found in secretions, offering mucosal protection and preventing respiratory infections in infants.
IgD: Monomer that initiates immune response on B cells.
IgE: Monomer involved in allergic reactions and defense against parasitic worms.

B and T Cell Functionality

Plasma Cells: Specialized B cells that produce specific antibodies.
Memory Cells: B cells retaining antigen memory for rapid response during re-exposure.
Clonal Selection: Process of producing numerous copies of a specific B cell to combat a disease.

Antigen-Antibody Reactions

Agglutination: Reduces infectious units, facilitating clearance by immune cells.
Opsonization: Coating antigens with antibodies to enhance phagocytosis.
Neutralization: Prevents pathogen adherence to host cells or neutralizes toxins.
Antibody-Dependent Cellular Cytotoxicity: Antibodies bind to target cells, leading to destruction by immune cells.
Complement Activation: Triggers inflammation and lysis of target cells.

Helper T and Cytotoxic T Cells

T Helper Cells: Activate macrophages and cytotoxic T cells; present antigens using MHC II.
T Cytotoxic Cells: Target infected or abnormal body cells; can differentiate into cytotoxic lymphocytes (CTLs).
Natural Killer Cells: Attack cells lacking MHC I and participate in antibody-dependent cytotoxicity.

Immune Regulation

T Regulatory Cells: Suppress immune response to prevent attack on self-antigens.
Cytokines: Proteins like interleukins stimulate immune cells and modulate immune responses.

Responses to Antigens

Primary Response: Initial exposure leads to slower antibody production due to the absence of memory cells.
Secondary Response: Subsequent exposures trigger rapid and efficient responses due to pre-existing memory cells.

Vaccination

Multiple Doses: Enhance immune efficiency through repeated exposures, increasing sensitivity to specific antigens.
Booster Shots: Reinforce immune memory by introducing the antigen again to prompt a robust immune response.

Immunity Classifications

Natural Immunity: Acquired without medical intervention; historically achievable.
Artificial Immunity: Acquired through medical means; not possible 2,000 years ago.
Active Immunity: Body independently produces antibodies in response to antigens, such as in vaccinations.
Passive Immunity: Antibodies introduced externally, such as through gamma globulin shots, not produced by the individual.

Description

Test your knowledge on Microbiology Chapter 17 with these flashcards. This chapter covers the essential concepts of innate and adaptive immunity, as well as humoral immunity. Perfect for reinforcing your understanding of the immune system.