immune system Flashcards
first line of immune defense
physical barriers
EXTERNAL
second line of immune defense
innate immunity
INTERNAL
third line of immune defense
adaptive immunity
HUMORAL AND CELL-MEDIATED RESPONSE
innate immune system
first line of defense and generates a rapid, nonspecific immune response
external immunity
skin - oily and acidic secretions from sweat glands kill microbes. skin is the first barrier to pathogens and viruses
antimicrobial proteins - lysozyme in saliva and tears break down microbial cell walls
cilia -lines the lungs and sweeps invaders out
gastric juice - stomach acid kills microbes
leukocytes
WBCs
come from stem cells in the bone marrow and can differentiate into different types of immune cells
neutrophils
function in the destruction of pathogens in infected tissues
monocytes
circulate in blood until they move into tissues via diapedesis where they develop into macrophages
macrophages
in tissues, they phagocytize cell debris and pathogens and are derived from monocytes
dendritic cells
ingest pathogens and stimulate the acquired immune response
mast cells
function in an allergic response, inflammatory response, and anaphylaxis (shock)
eosinophils
surround and destroy multicellular parasites
basophils
release histamine in the inflammatory response and recruited to tissues when needed
NK cells
attack abnormal body cells, either tumors or pathogen-infected cells
relative abundance of leukocytes
- neutrophils
- lymphocytes
- monocytes
- eosinophils
interferons
secreted by infected cells that stimulate neighboring cells to produce proteins to defend against viral infection
cytokines
chemical signaling molecules used in the immune response for cell-cell communication
interleukins
specific type of cytokine
- IL1 involved in the inflammatory reaction
- IL 2 triggers the adaptive immune response