VASCULAR AND PLATELET SYSTEM Flashcards
Production and development of megakaryocytes, the precursors to platelets, in the bone marrow
Megakaryopoiesis
Formation, production and development of blood platelets (thrombocytes)
Thrombopoiesis
specific hormone responsible for commitment of the megakaryoblast to differentiate further into more mature stages; primary regulator of thrombopoiesis;
stimulates differentiation and maturation of the megakaryocytes;
produced by the liver and kidneys
Thrombopoietin
Thrombopoietin is produced in
kidney and liver
a multipotent hematopoietic growth factor produced by activated T-cells, monocytes/macrophages and stroma cells
Interleukin 3
stimulates thrombopoietin production; promptly and transiently produced in response to infections and tissue injuries, contributes to host defense through the stimulation of acute phase responses.
Interleukin 6
together with TPO controls the production and release of platelets.
Interleukin 11
acts primarily on primitive cells of the hematopoietic cell lineages
preserve the viability of hematopoietic stem and progenitor cells, to influence their entry into the cell cycle and to facilitate their proliferation and differentiation
Stem Cell Factor
for proliferation of megakaryocytic progenitor cells
FLT-3 Ligand
inhibitors of hematopoiesis
TGFs & Interferon-gamma
Least mature progenitor
BFU meg
Most mature and enters endomitosis
LD CFU meg
is a form of mitosis that lacks telophase and cytokinesis
Endomitosis
Endomitosis lacks
telophase and cytokinesis
unique (Megakaryocyte ONLY) form of mitosis in which DNA replication and cytoplasmic maturation are normal but cells lose their capacity to divide.
Endomitosis
___ days for megakaryocytes to mature in the bone marrow
4-5
Most mature megakaryocyte are __N and __N
8N and 16N
Differentiating and mature megakaryocytes localize to the ______________ in preparation for movement into the bloodstream
abluminal (nonblood) surface of sinusoid-lining endothelial cells
