The Immune System Flashcards
what is the immune system?
cells and organs that destroy or neutralize pathogens that cause disease or death
what is the lymphatic system?
vessels, cells, organs that carry excess fluids to the bloodstream and filters pathogens from the blood
what is the interstitial fluid?
Fluid found in the spaces around cells. It comes from substances that leak out of blood capillaries
what is lymph?
the extra interstitial fluid that drains from your body’s cells and tissues
what is a lymph node?
small bean shaped organ throughout lymphatic system
where are lymph nodes found?
chest
neck
groin
abdomen
how many lymph nodes are there in the body?
500-600
what is the difference between the lymphatic system and the cardiovascular system?
lymph is pumped by body movement whereas blood is pumped by the heart
what is the function of the semi lunar valves in the lymphatic system?
they keep lymph moving towards the heart
what are the temporal phases of immune function?
- barrier defenses
- innate response
- adaptive response
what are the two main divisions of the immune system?
innate: (physical protection & phagocytes)
adaptive: (t lymphocytes/ b lymphocytes)
list the innate means of physical protection
skin - cough - tears - mucos - stomach acid
list the innate phagocytes
- monocytes
- macrophages
- neutrophils
- NK cells
- dendritic cells
list the adaptive T-lymphocytes
Helper T
Suppressive T
Cytotoxic T
list the adaptive B lymphocytes
clonal B lymphocytes
memory B lymphocytes
list the blood cells involved in immune response that arise from hematopoieses
- phagocytic cells
- lymphocytes
- cells with cytoplasmic granules
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how are t/b lymphocytes differentiated?
- surface protein markers t→ TCR/CD3/CD4/CD8 B→ check link (IgM/IgD/MHC II)
- molecules they secrete t→ cytokines b→antibodies
- maturation t → thymus , b → bone marrow
define antibodies
group of proteins that bind to pathogen-associated molecules
define antigens
pathogen-associated molecules on their surface
what are plasma cells, and what do they do?
they are the activated form of b-lymphocytes bound to pathogen surface antigens.
they secrete soluble antibodies
what is the function of t lymphocytes?
- secrete soluble factors to communicate with other cells of adaptive tissue
- destroy cells infected with intracellular pathogens
describe the structure of plasma cells?
they contain cytoplasm that is packed with rough endoplasmic reticulum that has protein synthesizing machinery
what is a natural killer cell? and what do they do?
circulating blood cell that contains cytotoxic granules in its cytoplasm, they destroy virally infected cells
what are the primary lymphoid organs?
- bone marrow: site of haematopoiesis
- thymus gland: site of energy storage
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where do t/b cells develop and mature
they are both developed in the bone marrow
HOWEVER, B→ mature in bone marrow
t→ mature in Thymus
where is the thymus gland located?
between the sternu and the aorta
compare and contrast the thymus cortex with the thymus medulla
- cortex:
epithelial cells/lots of thymocytes/macrophages/dendritic cells/densely packed
- medulla:
thymocytes migrate to it before leaving the gland
epithelial cells
dendritic cells
less packed
what are the secondary lymphoid organs
lymph nodes (LNs)
spleen
Peyer’s patches (PPs)
mucosal tissues- the nasal associated lymphoid tissue (NALT)
adenoids
and tonsils
what do the secondary lymphoid organs do?
fighting off germs and foreign substances
what is a naive lymphocyte?
one that has left primary organ and enter secondary lymphoid organ
what do the secondary lymphoid organs have in common?
- presence of lymphoid follicle where lymphocytes form
- reticular fibers (fixed macrophages)
- germinal centers (site of division and differentiation)
- high endothelial venules (allows cells in blood to enter tissues)
