organs and cells of immune system Flashcards
what happens in the primary lymphoid organs?
cells of immune system develop ( production and maturation)
what are the primary lymph organs?
bone marrow and thymus
what happens in the secondary lymphoid organs?
cells of immune system function/interact with antigens
what are the secondary lymph organs?
lymph nodes spleen tonsils adenoid RE system
how are secondary and primary connected?
blood and lymphatic vessels
where is bone marrow found?
medullary cavity of long bone
hematopoietic stem cells aka
CD34+ cells
where are HP stem cells found and what do they give rise to?
bone marrow
cells of immune system and blood cells
what dictate what cell is formed from HP stem cells?
cytokines and growth factors
when HP cell becomes myeloid stem cell what can it give rise to?
macrophages/monocytes granulocytes eosoniphil RBC platelets
when HP cell becomes lymphoid stem cell what can it give rise to?
T and B cells
NK cells
what is thymus derived from?
endoderm = 3rd pharyngeal pouch
ectoderm = 3rd brachial cleft
mesenchymal element
where is thymus located?
anterior mediastinum
what connects 2 lobes of thymus?
isthmus
what occurs in thymus?
T cell maturation and differentiation (positive and negative selection)
positive selection
T cell can bind to mhc class I / ii with at least weak affinity