Immunology Flashcards
(80 cards)
What are the three lines of defense?
physical barriers, innate immune system, and adaptive immune system
Innate immune system
inherited mechanisms that protect the body from pathogens in a nonspecific way (has no memory of prior exposure to the pathogen)
adaptive immune system
inherited mechanisms leading to the synthesis of molecules that target pathogens in a specific way (retains a cellular memory of the pathogen)
What are some examples of physical barriers that help protect us?
tight junctions between epithelial cells; mucus layer secreted by many epithelial cells
Innate immunity and adaptive immunity constitute the ________
immune system
_______ and their derivatives, along with several types of plasma proteins, are responsible for the activities of the two immune systems
leukocytes
Some WBC are ______ that engulf bacteria and other cellular debris
phagocytosis
lymphocytes form in the bone marrow and then migrate to the ______
thymus
The innate immune system recognizes ______________ that are associated with pathogenic organisms but are absent in the host
pathogen-associated molecular patterns
toll-like receptors
found on the cell surface and within the cell on various membrane-bound compartments (a class of pattern recognition receptors)
All of our epithelial surfaces, inside and out, are protected by antimicrobial peptides called ______
defensins
Defensins attack _____ of pathogens- thereby killing the cells
their plasma membranes
Do defensins play a role in innate or adaptive immunity?
innate
Infection by most pathogens involves ______
inflammation
cell-surface receptors on _____ recognize and bind to surface molecules on the pathogen- activating this ______ to engulf the pathogen
macrophages
Activated macrophages secrete ________, which bind to receptors on other host cells and through signal transduction pathways, trigger a response
cytokines
tissue damage activates ______, which releases histamine, an inflammatory signaling molecule
mast cells
Histamine and cytokines…
dilate blood vessels and increase blood flow
Cytokines make the blood vessel wall stickier, causing circulating ______ and _______ to attach to it
neutrophils, monocytes
Neutrophils and monocytes are attached to the infection site by ________ secreted by activated macrophages
chemokines
Monocytes differentiate into _________ and along with the neutrophils, engulf the pathogens
macrophages
Antigen
a foreign molecule that triggers an adaptive immune response
Antigens are recognized by two types of lymphocytes…
B cells and T cells
______ differentiate from stem cells in the bone marrow and are carried in the blood to capillary beds serving the tissues and organs of the lymphatic system
B cells