Immunology

A set of flashcards designed to help students review key concepts and vocabulary related to immunology, focusing on the immune system's organization, cells, and responses.

Immunity

The ability of an organism to resist disease or infection.

Innate Immunity

The nonspecific first line of defense against pathogens; fast response.

Adaptive Immunity

A specific immune response that develops over time; involves recognition of specific antigens.

Leukocytes

White blood cells responsible for immune responses.

Lymphocytes

A type of leukocyte that includes B cells and T cells, involved in adaptive immunity.

Granulocytes

A category of white blood cells that contain granules in their cytoplasm; includes neutrophils, eosinophils, and basophils.

Inflammation

The body's response to injury, characterized by redness, heat, swelling, and pain.

Primary Lymphoid Organs

Organs where lymphocytes mature; includes bone marrow and thymus.

Secondary Lymphoid Organs

Organs where lymphocytes are activated; includes lymph nodes and spleen.

Active Immunity

Immunity developed by exposure to an antigen.

Passive Immunity

Immunity acquired by transferring antibodies from another individual.

Phagocytes

Cells that engulf and digest pathogens.

Natural Killer Cells

A type of lymphocyte that targets and kills virus-infected cells and tumors.

Antigen-Presenting Cells

Cells that process and present antigens to T lymphocytes; includes dendritic cells and macrophages.

Microbial Antigen

A substance from a microbe that elicits an immune response.

B Lymphocytes

A type of lymphocyte that produces antibodies.

T Lymphocytes

A type of lymphocyte involved in cell-mediated immunity.

Acute Phase Proteins

Proteins produced in response to inflammation that help control the immune response.

Cytokines

Small proteins that mediate and regulate immunity and inflammation.

Complement System

A group of proteins that enhance the ability of antibodies and phagocytic cells to clear microbes.

Clonal Selection Hypothesis

Theory explaining how specific lymphocyte clones proliferate in response to antigens.

Primed Lymphocytes

Lymphocytes that have been activated by exposure to an antigen.

Memory Cells

Long-lived lymphocytes that respond more efficiently upon re-exposure to an antigen.

Exudate

Fluid that leaks out of blood vessels during inflammation.

Mucosal-Associated Lymphatic Tissue (MALT)

Tissue that protects mucosal surfaces from infection; includes tonsils and Peyer's patches.

Interferons

Proteins produced by host cells in response to viral infections, with antiviral activity.

Tolerance

The immune system's ability to avoid attacking the body's own tissues.

Pathogen-Associated Molecular Patterns (PAMPs)

Molecular patterns recognized by the innate immune system.

Dendritic Cells

Professional antigen-presenting cells that activate T cells.

Neutrophils

The most abundant type of white blood cell; first responders to infection.

Eosinophils

White blood cells primarily involved in combating parasitic infections and allergic reactions.

Basophils

White blood cells that release histamine during allergic reactions.

Toll-Like Receptors (TLRs)

Proteins that recognize specific patterns of pathogens and activate the immune response.

Myeloid Lineage Cells

Cells derived from myeloid progenitors; includes macrophages and granulocytes.

Lymphoid Lineage Cells

Cells derived from lymphoid progenitors; includes B cells and T cells.

Cytotoxic T Cells

T cells that kill infected or cancerous cells.

Helper T Cells

T cells that assist in activating other immune cells.

C-reactive Protein (CRP)

A marker of inflammation that is part of the acute phase response.

Vasodilation

The widening of blood vessels to increase blood flow during inflammation.

Diapedesis

The movement of leukocytes through the endothelium to reach the site of infection.

Fever

Increase in body temperature as a systemic response to infection.

Antigens

Substances that provoke an immune response.

Immunocompetent

Refers to cells, particularly lymphocytes, that are capable of responding to pathogens.

Subpopulations of T Cells

Different types of T cells, including helper, cytotoxic, and regulatory T cells.

Integrins

Receptors on leukocytes that mediate adhesion to the endothelium.

Selectins

Adhesion molecules that help leukocytes roll along the endothelium.

Clonal Expansion

The rapid multiplication of lymphocytes upon activation by specific antigens.

Functional Differences Between Immune Cells

Differences in roles such as antigen presentation, antibody production, and cytotoxic activities.

Endothelium

The thin layer of cells lining blood vessels involved in leukocyte migration.

Chemotaxis

Movement of cells towards a chemical gradient, often used by leukocytes to reach sites of infection.

Infection

The invasion and multiplication of pathogenic microorganisms.

Immune Cell Training Center

Sites (primary lymphoid organs) where immune cells learn to recognize pathogens.

Hemoglobin

Protein in red blood cells that carries oxygen, referenced as a contrast to immune cells.