Lecture 13: Hematopoiesis Flashcards
Totipotent
Give rise to all cells of an organism
Pluripotent
Give rise to all cells of the embryo and subsequently adult tissues
Multipotent
Give rise to different cell types of a given lineage
Embryonic stem cells
Pluripotent
Derived from inner-cell mass of blastocyst
Adult stem cells
Multipotent
Hematopoietic site 2-8 weeks gestation
Islands of hematopoiesis are found in the yolk sac wall
Give rise to nucleated erythrocytes
No leukocytes yet
Hematopoietic site 8-28 weeks gestation
Hematopoiesis first occurs in the liver and then the spleen
Normally ceases around time of birth
Hematopoietic site 6 months gestation to birth and beyond
Hematopoiesis occurs in red bone marrow
Red marrow found where prior to and after puberty
Prior- Skull, ribs, sternum, vertebrae, clavicles, pelvis, long bones
After- Same except not in long bones
Red blood cell formation can occur where in certain disease states
Liver and Spleen
Stroma
Contains fibroblasts, reticular, adipose and endothelial cells
Synthesizes and secretes hematopoietic growth factors
Parenchyma
Consists of various lineages of hematopoietic cells in different stages of differentiation
Sinusoids
Endothelial-lined spaces that connect arterial and venous vessels
Provides access for mature blood cells to move into the circulation
Hematopoietic cords
Bands of parenchyma and stroma lying between the sinusoids
Hematopoietic stem cells are (potency)
Pluripotent
Hematopoietic stem cells give rise to
Myeloid stem cells- give rise to all blood cell lines besides lymphocytes
Lymphoid stem cells- give rise to lymphocytes
Leukocytes include
Granulocytes and agranulocytes
Granulocytes include
Neutrophils, basophils, Eosinophils
Agranulocytes include
Monocytes, lymphocytes
Myeloid stem cells give rise to
Erythroid CFU- Produce RBC Megakaryocyte CFU- Produce RBC Basophil CFU-WBC Eosinophil CFU-WBC Granulocyte-macrophage CFU-WBC
Lymphoid stem cells give rise to what, which mature where
T-cell progenitor- matures in thymus
B-cell progenitor- matures in bone marrow
Cells normally found in circulation
Monocyte Band cell Neutrophil Platelets Eosinophil/basophil Reticulocyte Erythrocyte
Cells which can divide
Monoblast Myeloblast Premyelocyte-myelocyte Proerythroblast Basophilic erythroblast Polychromatophilic erythroblast
