Barrier Defenses and Immune Responses

This set of flashcards covers key vocabulary related to the immune system, including definitions of important terms and concepts.

Innate Immune Response

A rapid but nonspecific response involving physical barriers preventing pathogens from entering the body.

Phagocyte

A cell that surrounds and engulfs particles or cells through phagocytosis, serving as the first line of immunological defense.

Macrophage

A type of phagocytic cell found primarily in body cavities, functioning as a key player in the innate immune response.

Natural Killer Cells (NK Cells)

A type of lymphocyte that induces apoptosis in cells affected by intracellular pathogens.

Cytokine

A signaling molecule that allows communication between cells over short distances, inducing physiological changes.

Chemokine

A soluble chemical mediator that attracts cells from longer distances through chemotaxis.

Vasodilation

Increased diameter of blood vessels, responsible for heat and redness of inflamed tissue.

Antigen

A chemical structure on the surface of a pathogen that is recognized by B or T lymphocyte receptors.

Plasma Cells

B cells that have differentiated and gained the ability to secrete soluble antibodies.

Primary Adaptive Response

The initial immune response to a pathogen, which is often slower and has more severe symptoms.

Secondary Adaptive Response

A faster and stronger immune response upon re-exposure to the same pathogen.

T-Cell Mediated Immune Response

An immune response that involves T-cells making decisions on how to attack a pathogen.

Active Immunity

Resistance to pathogens acquired during an adaptive immune response.

Passive Immunity

The transfer of antibodies to individuals without requiring an active immune response.

Lymphatic System

The system of vessels, cells, and organs that carries excess fluids to the bloodstream and filters pathogens.

Lymph Node

A small bean-shaped organ that is a major staging area for the development of immune responses.

Dendritic Cells

Cells in lymph nodes that internalize and kill pathogens, supporting immune response.