Classification oflymphoid tissueA. Diffuse L.TB. Lymphoid nodules
Classification of lymphoid tissue A. Diffuse L.T B. Lymphoid nodules
A.Diffuse LT:no clear boundarymainly consists of TCpostcapillary venules:-highendothelial venules-opening forLC enterLT from bloodpostcapillary venule:high endothelia
A. Diffuse LT: no clear boundary mainly consists of TC postcapillary venules: -high endothelial venules -opening for LC enter LT from blood high endothelia
B.Lymphoid nodule:spherical or ovoidhaveclearboundariesmainly composed of BLCgerminal center: stained paleDistribution: lamina propria of digestiveand respiratory tract.AgPrimary ~Secondary ~
B. Lymphoid nodule: spherical or ovoid have clear boundaries mainly composed of BLC germinal center: stained pale Distribution: lamina propria of digestive and respiratory tract. Primary ~ Secondary ~ Ag
Secondary lymphoid noduleCapLightzoneDarkzoneGerminalcenter
Cap Light zone Dark zone Germinal center + Secondary lymphoid nodule
Lymphoid organsCentrallymphoid organs(Thymus,Bonemarrow)Places for differentiation and maturation,without stimulationdevelopedearliersendLCtoPLOandLTtwo weeksbeforeborne>Peripherallymphoid organs(lymph node, spleen, tonsil)Placestoproceedimmunereactionsdevelopedlatercell proliferation need antigen stimulation-antigen dependent
Lymphoid organs Central lymphoid organs (Thymus, Bone marrow) Places for differentiation and maturation, without stimulation developed earlier send LC to PLO and LT two weeks before borne Peripheral lymphoid organs (lymph node, spleen, tonsil) Places to proceed immune reactions developed later cell proliferation need antigen stimulation- antigen dependent