lymph nodes & spleen Flashcards
primary lymphoid organs
sites of lymphocyte formation
secondary lymphoid organs
site where B and T cells proliferate
lymph fluid drains from
site of infection
in lymph fluid, __ are activated
dendritic cells
dendritic cells express
MHC I, MHC II, B7
dendritic cells present to
T cells
lymphoid follicles are found in
cortex of lymph node
lymphoid follicles are site of
B cells activation
follicular dendritic cells are
permanent cells of lymph nodes
__ are imp reservoir to HIV
follicular dendritic cells
primary lymphoid follicles are
inactive
secondary lymphoid follicles contain
germinal center
what happens are germinal center
B cell growth and class switching
2 key features of paracortex
- contain T cells activated by dendritic cells
- contain high endothelial venues
paracortex is underdeveloped in
T cell def disorders (DIGeorge syndrome)
medullary sinuses contain
macrophages (which lead to phagocytosis)
medullary cords contain
plasma cells secreting antibodies
spleen role
filters blood
white pulp
exposure to B & T cells
exposure to macrophages
red pulp
filters blood in sinusoids & removes old RBCs
3 parts of white pulp
- marginal zone
- follicles
- periarteriolar lymphocyte sheath (PALs)
marginal zone role
macrophages
remove debris
dendritic cells process antigens
follicles contain
B cells
PALs contain
T cells
splenic dys leads to increased risk from
encapsulated organisms
loss of marginal zone macrophages leads to
decreased phago & loss of opsonization
predominant pathogen for sepsis
strep pneumo
nuclear remnants normally cleared by spleen, if present signify a splenic dys
howell jolly bodies
thrombocytosis is due to failure of
spleen to remove platelets
