opal Flashcards
all immune cells come from
bone marrow
B-cells are activated in
spleen and lymph nodes
T-cells mature in
thymus
tonsils and adenoids are examples of
gut-associated lymphoid tissue
leukocytes
Cells of the immune system involved in protecting body against infectious disease and foreign invaders.
All white blood cells derived from a multipotent cell in the bone marrow known as a hematopoietic stem cell. Leukocytes are found throughout the body, including the blood and lymphatic system.
skin
physical barrier and secretes antimicrobial compounds like defensins
mucous
on mucous membranes traps pathogens; in respiratory system, mucous is propelled upward by cilia and can be swallowed or expelled
tears and saliva contain
lysozyme, an antibacterial compound
defenses of gut
stomach produces acid, which kills most pathogens. colonization of gut helps prevent outgrowth by pathogenic bacteria through competition
complement system
can punch holes in cell walls of bacteria to make them osmotically unstable
interferons
given off by virally infected cells and help prevent viral replication and dispersion to nearby cells
macrophages
ingest pathogens and present them on major histocompatibiltiy complex (MHC) molecules. they also secrete cytokines
MHC-I
present in all nucleated cells. present endogenous antigen (proteins from within the cell) to cytotoxic T-cells (CD8+ cells)
MHC-II
present in professional antigen-presenting cells (macropahges, dendritic cells, some B-cells, and certain activated epithelial cells) and display exogenous antigen (proteins from outside the cell) to helper T-cells (CD4+ cells)
dendritic cells
antigen-presenting cells in the skin
natural killer cells
attack cells not presenting MHC molecules, including virally infected cells and cancer cells
granulocytes
include neutrophils, eosinophils, basophils