新版小儿造血和血液特色（英文）课件.ppt

Development of the Hematopoietic System Blood Cell Counts Dr.Jie Yu, MD. Professor The department of Pediatric, Hematology/Oncology Contents Development of hematopoietic system Hematopoietic organs Hematopoietic blood cells Characteristic of cell counts and hemoglobin RBC and Hb level Hemoglobin WBC/Platelet/Blood volume Anemia Development of Hematopoietic System In the embryo and fetus, constant changes characterize all phases of hematopoiesis. Development of Hematopoietic Organs Fetal hematopoiesis Mesoblastic Hematopoiesis Hepatic Hematopoiesis Myeloid Hematopoiesis Hematopoiesis after birth Development of Hematopoietic Organs Fetal hematopoiesis Hematopoiesis after birth Bone marrow hematopoiesis Extrmedullary hematopoiesis Development of Hematopoietic Organs Hematopoiesis after birth Bone marrow hematopoiesis All blood cells are produced in the marrow after 2nd trimester Newborn and early infancy: red marrow 5-7yr : yellow marrow Extramedullary hematopoiesis Development of Hematopoietic Organs Hematopoiesis after birth Bone marrow hematopoiesis Extramedullary hematopoiesis In diseases status: red cell production? hematopoietic tissue?. blood production expands to replace fatty marrow. blood cells production extends to extramedullary sites ( liver and spleen). Development of the Hematopoietic Blood Cells Pluripotent Stem Cells: which are capable of both self-renewal and of clonal maturation into all blood cell lineages. Progenitor cells differentiate under the influence of hematopoietic growth factors Table 2.The Development of Blood Cells Blood Cell Counts  and Hemoglobin Fig2. Peripheral Blood Cells RBC and Hb Level At B