What are components of hematopioetic system?

Myeloid Tissues (Bone marrow and cells derived from it) Lymphoid Tissues (Thymus, Lymph nodes, Spleen) Lymphoid Organs (Cells of the immune system are distributed through body in 1. blood, lymph, epithelial and connective tissues 2. lymphoid nodules 3. lymphoid organs (Lymph nodes, Spleen, Thymus, Bone marrow) Mucosa-Associated Lymphoid Tissue (MALT) (Lungs, Peyer’s patches, Tonsils, Sites of IgA secretion to protect mucosal surfaces from infection) Thymus • Thymus is site of T-cell differentiation, into CD4+ or CD8+ T-cells, Thymic-blood barrier, with non-fenestrated endothelial cells, No afferent lymphatics