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