Hematopoiesis Flashcards
What are the two compartments within the bone marrow
Vascular & hematopoietic
What do adventitial cells (reticular cells) secrete?
Hematopoietic growth factors, produce reticular fibers
Which cells does the common lymphoid progenitor give rise to?
T, NK, and B cells
Which cells does the common myeloid progenitor give rise to?
Platelets, RBCs, Neutrophiles, Eos, Bas
Which phase of hematopoiesis occurs during 2 to 8 weeks gestation
Mesoblastic or yolk sac
What kind of erythrocytes are formed during the yolk sac phase?
Nucleated
When does the hepatic phase occur?
2 to 7 months intrauterine
What erythrocytes are produced during the hepatic phase?
Anucleate erythrocytes followed by megakaryocytes and granulocytes
When does the splenic phase occur?
10th week to 6-7 months intrauterine
When does the bone marrow phase occure?
6 months intrauterine until death
Site of active hematopoiesis
red marrow
When does yellow marrow begin to replace red marrow?
after 4-5 years of age
Site of less active hematopoiesis
Yellow marrow
The way in which adventitial cells regulate their size
Regulating lipolysis
After age 20 where are sites of active hematopoiesis?
Sternum, ilia, vertebral bodies, ribs, clavicles, cranial bones, and proximal ends of the femur and humerus
What is the purpose of reticular fibers in the hematopoietic compartment?
Form a mesh around the areas of blood cell formation, (mechanical support)
What is the monophyletic theory?
There is a pluripotential hematopoietic stem cell that can give rise to all the formed elements of blood
The stroma of the hematopoietic compartment consists of:
Adventitial cells, Reticular fibers, and macrophages
Where does erythropoiesis occur?
Erythroblastic islets
During erythropoiesis what is responsible for: supplying iron for heme synthesis, produce growth factors, phagocytize extruded nuclei
Macrophages
What is the order of Erythropoiesis?
Proerythroblasts, Basophilic erythroblasts, polychromatophilic erythroblasts, orthochromatic erythroblasts, reticulocytes, mature erythrocytes
Which common myeloid progenitor gives rise to the 3 types of granulocytes, monocytes, platelets, and erythrocytes?
CFU-GEMM
What is the first morhologically recognizable precursor cells in the granulocyte pathway?
Myeloblasts
What is the first morphologically recognizable precursors to erythrocytes?
Proerythroblasts
