Bone Marrow and Hematopoiesis Flashcards
(32 cards)
In what stage of hemopoiesis does blood form in the mesenchyme and yolk sac; 2nd and 3rd week of gestation
Mesoblastic (yolk sac phase)
The yolk sac contains precursors of both … and… cells
blood and germ cells
In what stage of hemopoiesis does blood form in the liver and spleen; 6th week of gestation
haptic
In what stage of hemopoiesis does blood form in bone marrow (and other lymphatic tissues); 4th and 5th month
myeloid phase
After birth hemopoiesis only occurs where?
red bone marrow and lymphatic tissues
If the bone marrow is damaged in an adult, what organs can resume blood cell formation
spleen and liver
Under adverse conditions such as … or …, yellow marrow reverts to red marrow.
hypoxia or severe loss of blood
Barrier between the blood and the hematopoietic tissue. Its wall consists of three layers
Vascular Sinuses
The continuous endothelium layer of the vascular sinuses is composed of simple squamous cells joined together by … therefore no mature cells pass between the endothelial cells, but through them (Transcellular)
junctional complexes
Cover most of the outer surface of vascular sinus endothelium; synthesize the reticular fibers in marrow; produce cytokines for the proliferation and maturation of blood cell precursors; make up the adipose cells of yellow marrow
adventitial reticular cells
adipocytes in yellow marrow are simulated by …
glucocorticoids
Where do blood cells develop?
Hematopoietic Cords
Houses the red blood producing cells; usually macrophages are found here
erythroid compartment
Usually macrophages are found in the center of erythroid cell clusters known as …
erythroblastic islets
All blood cell types originate from one pluripotential stem cell
Monophylectic Theory
The pluripotential stem cell (PPSC) produces two cell lineages … and … which make up the multi potential stem cell lineages
lymphoid and myeloid cell
Precursor cells (CFUs) are also known as …
blast cells i.e. myeloblasts, erythroblasts, etc.
The first recognizable cell in the series of erythrocyte development is the …
Pronormoblast (Proerythroblast)
Proerythroblasts have a basophilic cytoplasm due to the presence of ribosomes actively synthesizing …
hemoglobin
In what stage of erythropoiesis does the nucleolus become no longer visible?
basophilic normoblast
In what stage of erythropoiesis is the Hb content of the cytoplasm increases. Hb is acidophilic making the cytoplasm stain both acidophilic and basophilic
polychromatophilic normoblast
Reticulocytes leave the bone marrow through the …
sinuses
Iron bound to heme is released and stored in the spleen as … for reuse
hemosiderin or ferritin
Heme is partially degraded to … and eventually excreted via the gallbladder in stool or in the urine
bilirubin
