immune system Flashcards
antigens
substances on the surfaces of agents that act to identify them, to the body, as being native or foreign.
Pathogens
organisms that cause disease in humans
allergies
an immune response to a foreign agent that is not a pathogen
autoimmune disease
the immune system mistaking part of the body as a pathogen.
tissue/organ rejection
incompatibilities generated by the immune system
EX: someone with type A blood receives type B blood
External Innate immune system
-first line of defense
- skin, hair, mucus, saliva, tears, normal flora, secretions (acid, salt, enzymes)
Internal Innate immune system
-second line of defense
- internal defenses activated
-inflammation, production of interferon, antimicrobials, NK lymphocytes, and ingestion of pathogens by phagocytes.
antimicrobial
a substance that kills or inhibits growth of microorganisms with minimal damage to the host
- in mucus, tears, and saliva
phagocytosis
ingestion of particles by a cell or phagocyte
macrophage
a large phagocytic white blood cell that ingests foreign material
T cells
white blood cells that mature in the thymus and participate in an immune response
antigen-presenting cell (APC)
after consuming the pathogen, the macrophage is able to put parts of the ingested antigens on its cell membrane to alert patrolling T cells.
- dendritic cells and b cells can function the same way
dendritic cells
-subclass of APCs
-antigen-presenting cells that process antigen material and present it to T cells
B cells
- subclass of APC and a type of lymphocyte
-lymphocytes that mature in bone marrow and make antibodies in response to antigens
cytokines
cell signaling molecules releasing primarily by helper T-cells and macrophages. certain cytokines activate cytotoxic T-cells.
-types: interleukines interferons
histamine
a white blood cell secretion that triggers capillary permeability and vasodilatation
- basically, makes it easier for more white blood cells to leak from capillaries into the area in need of defense
inflammation
the resulting redness, swelling, heat, and pain in an area of defense by innate immunity
interferons
proteins secreted by leukocytes when they are infected with viruses
-prevent virus replication
-a type of cytokine
Adaptive Immune system
- third line of defense
- a kind of passive or active immunity in which antibodies to a particular antigen are present in the body.
-deals with perceived pathogens at a slower rate
lymphocytes
a category of white blood cells that include killer cells, B cells, T cells, and what T cells become.
Helper T cell
secrete interleukins, chemical messengers that trigger the action of other cells
-activate cytotoxic t cells
-activate b cells
cytotoxic t-cells
triggered by helper t cells that attack foreign cells
memory cells
recognize foreign particles that is was exposed to
- repond so quickly to an antigen upon re-exposure that the body is immune to developing symptoms the second time
cell-mediated immunity
a type of adapted immunity in which T lymphocytes attack parasitic worms, cancer cells, transplanted tissues, or cells that contain pathogens
