Chapter 24: The Adaptive Immune Response

Flashcards covering key vocabulary and concepts related to the adaptive immune response.

Immunity

The active ability of an organism to resist infection.

Innate Immunity

The body’s built-in ability to recognize and destroy pathogens; includes an immediate response (0-4 hours) and an early induced response (4-96 hours).

Adaptive Immunity

Acquired ability to recognize and destroy pathogens; typically involves a late response (over 96 hours).

Antigens

Fragments of macromolecules that can elicit an immune response.

Antibody

Proteins made by the body in response to antigens, circulating in the blood to initiate events that destroy the target.

Major Histocompatibility Complex (MHC)

A molecule that binds antigens and presents them on the surface of antigen presenting cells (APCs) for recognition by T cells.

Immunogenicity

The effectiveness of an antigen in generating an immune response.

Cross Protection

The phenomenon where exposure to one pathogen can protect against another if their antigens are similar.

Cytotoxic T Cell

A type of T cell that destroys infected host cells by inducing apoptosis.

Helper T Cell

A type of T cell that activates B cells and other immune cells by secreting cytokines.

Opsonization

The process by which antibodies mark pathogens for phagocytosis.

Memory B Cells

B cells that remain after an infection has resolved, allowing for a faster response to future exposures to the same antigen.

Complement System

A group of serum proteins that work together to kill bacteria, with three activation pathways: alternative, classical, and lectin.

Isotype

Different classes of antibodies defined by their heavy chain (e.g., IgG, IgM).

Idiotype

The unique antigen-binding site characteristic of a specific antibody.

Allotype

Differences in antibody constant regions between individuals.

Apoptosis

Programmed cell death.

Antigen Presenting Cells (APCs)

Cells that present antigens to T cells, essential for T cell activation.

T Cell Activation

The process by which T cells are stimulated to respond to antigens presented by APCs.