The Adaptive Immune Response

Flashcards covering key concepts from the adaptive immune response lecture.

Adaptive Immune Response

An immune response that matures throughout life, is directed against specific organisms, and involves B and T cells.

B and T Cells

Lymphocytes involved in the adaptive immune response; B cells produce antibodies, while T cells provide cell-mediated immunity.

Secondary Lymphoid Organs

Sites where lymphocytes gather to encounter antigens, including lymph nodes, spleen, tonsils, and appendix.

Memory Cells

Long-lived B and T cells that respond rapidly to subsequent encounters with the same antigen.

Humoral Immunity

A type of adaptive immunity mediated by antibodies produced by plasma cells which eliminate extracellular pathogens.

Cellular Immunity

Type of adaptive immunity mediated by T cells which eliminate intracellular pathogens.

MHC (Major Histocompatibility Complex)

Molecules on cells that present antigens to T cells, aiding in the recognition of infected or abnormal cells.

Antigen-Presenting Cells (APCs)

Cells that process and present antigens to T cells, including dendritic cells and macrophages.

Clonal Selection Theory

The idea that when an antigen binds to a specific B or T cell, that cell proliferates to produce a large number of clones with the same specificity.

Cytokines

Chemical messengers produced by immune cells that help regulate the immune response.

Passive Immunity

Immunity acquired through the transfer of antibodies from one individual to another, without the host's immune system being activated.

Naturally Acquired Immunity

Immunity gained through natural exposure to pathogens, leading to immune response.

Affinity Maturation

The process in which B cells undergo mutations to enhance their ability to bind to antigens during immune responses.

Class Switching

Process that allows B cells to change the class of antibodies they produce, often switching from IgM to IgG.

IgG

The most prevalent antibody class, involved in secondary immune responses, neutralizing toxins, and facilitating phagocytosis.

IgM

The first antibody produced in response to an infection; circulates as a pentamer with multiple binding sites.

IgA

An antibody found in mucosal areas and secretions, providing protection at entry points for pathogens.