Origin of cells of immune system

All components of the blood, including immune cells are originated from hematopoietic stem cells these cells are highly differentiated into progenitor cells to give different cells.The formation and development of hematopoietic stem cells beginsin the early embryonic stages,lately these cells migration to liver, spleen,and differentiated in bone marrow in one of two pathways.

1. Myeloid progenitor cells can differentiate into:

1. Megakaryocytes, which are differentiated into platelets.

1. Erythroblasts, which are multiplyand differentiated into RBCs.

1. Myeloblasts, which can differentiate into neutrophils, eosinophil, and basophil.

1. Monoblasts, which can differentiate into monocyte and dendritic cells.

1. Lymphoid progenitor can be differentiating into:

• T-lymphocytes, which are responsible for the cellularimmune response.

• B-lymphocytes, which produce antibodies (humoral immuneresponse).

• Natural killercells (NKs).