Megakaryopoiesis Flashcards
Stages , Platelet Structure , Henostasis
Proceeds initially through a phase chracterized by mitotic division of a progenitor cell.
Megakaryopoiesis
Maturation of megakaryocyte is through.
Endomitosis
Earliest recognizable stage
Megakaryocyte
Cytoplasm has aggregates of granular material into masses seperated by DMS
Metamegakaryocyte
At least 4 nuclei can produce platelets
Megakaryocytes
Contains mithochondria and primitive endoplasmic reticulum
Megakaryoblast
Has a diameter of 15 - 50 um
Megakaryoblast
Function as the future membrane system of platelets
DMS
Abundant cytoplasm contains numerous small granules with a reddish blue hue
Megakaryocyte
A very large cell
Metamegakaryocyte
Size is larger to megakryoblast
Promegarkaryocyte
Nucleus is multilobed and ploidy ranges from 4N to 64N
Metamegakaryocyte
Decreased nuclear cytoplasmic ratio
Metamegakaryocyte
Cytoplasm is devoid of specific organelles
Megakaryocyte
Nucleus usually undergone one or two division
Promegakaryocyte
Contain single, centrally located nucleus or multiple round and oval nuclei with nucleoli
Megakaryoblast
Bluish stained granules
Promegakaryocyte
Abundant cytoplasm contain numerous small granules with reddish blue hue
Megakaryocyte
Platelet structure
- Peripheral zone
- Submembrane Area
- Sol gel zone
- Organelle Zone
Act as open communication channels into the platelet cytoplasm
Glycocalynx
Contains Glycoproteins
Thickness 10 - 50nm
Glycocalyx
Physical and chemical barrier
Plasma membrane
Contain structure to prevent contact between organelles and the cell membrane.
Submembrane area
Contribute to the regulation of normal platelet doscoid shape
Microfilaments
