Vocabulary

adaptive immunity

immune system's ability to destroy specific targets and "remember" those targets

antibody

Y-shaped protein that recognizes and binds to a specific antigen

antigen

substance that is recognized by surface antibodies or other immune cells to prompt an immune response

B cell

lymphocyte that originates and matures in the red bone marrow and produces antibodies, which bond to pathogens and neutralize them

basophil

leukocyte (white blood cell) from the myeloid lineage that releases histamine and heparin to promote inflammation

chemotaxis

movement of a cell in response to a chemical stimulus

cytokine

one of a family of chemical messengers that regulate several different immune functions

cytolysis

rupture of the cell membrane that causes the cell to burst apart

dendritic cell

antigen-presenting cell that elicits an adaptive immune response from T cells

diapedesis

movement of leukocytes through capillary walls from the bloodstream into tissue as part of the inflammatory response

eosinophil

leukocyte (white blood cell) from the myeloid lineage that contains granules, releases cytotoxic chemicals to kill large parasites, and plays a role in allergies and asthma

fever

systemic response to pathogens that inhibits bacterial growth and aids in the overall immune response by increasing leukocyte mobility and T cell proliferation

granulocyte

immune cell that contains granules in the cytoplasm

inflammation

local response to injured tissue that results in an increased blood flow to the affected site and triggers a cell-mediated immune response if the second line of defense fails

innate immunity

nonspecific, immune response, including chemical and physical barriers and internal cellular and chemical defenses

interferon

cytokine released from cells infected by a virus that causes a series of protective changes in neighboring cells

interleukin

cytokine released by macrophages that attracts leukocytes to the site of an infection

leukocyte

specialized immune cell that originates from hematopoietic stem cells found in the red bone marrow

lymphocyte

specific type of leukocyte that includes several different types of specialized immune cells, all of which are primarily found in lymph (interstitial fluid that has entered the lymphatic system)

macrophage

phagocytic cell that patrols tissues in search of pathogens

mast cell

immune cell that lives for a long time in the body's tissues and releases chemicals, triggering allergic-mediated responses from the immune system

monocyte

large phagocytic leukocyte (white blood cell) that circulates in the bloodstream. When attracted to tissues, it differentiates into a macrophage.

neutrophil

most common type of leukocyte (white blood cell) in the body. It migrates from the bloodstream to carry out phagocytosis at the site of an injury.

opsonin

molecule that promotes phagocytosis by macrophages and other phagocytic immune cells

phagocytosis

process by which cells such as macrophages engulf and digest pathogens or other material

phagosome

vesicle that surrounds an engulfed particle

T cell

leukocyte produced by red bone marrow that migrates to the thymus gland, where it matures. They play a role in eliciting the adaptive immune response