MTAP W4 (Hematology: Checkpoint notes: Megakaryopoiesis/Platelets) Flashcards
fragments of the cytoplasm of mature megakaryocytes
platelets
progenitor cell of megakaryocytopoiesis/thrombopoiesis
CFU-GEMM
3 stages of megakayocytes lineage-committed progenitor cells
least mature; clones hundreds of daughter cells
BFU-Meg
3 stages of megakayocytes lineage-committed progenitor cells
intermediate; clones scores of daughter cells
CFU-Meg
3 stages of megakayocytes lineage-committed progenitor cells
more mature; undergoes first stage of endomitosis
LD-CFU-Meg
influence proliferation of the stem and progenitor cells
- SCF/stem cell factor
- IL-3
- GM-CSF
support megakaryocyte production, primarily maturation
- IL-6
- IL-11
major humoral factor regulating platelet development which influences all stage of megakaryocyte production
thrombopoietin
the development of megakaryocytes
nuclear division without cytoplasmic division
endomitosis
a single megakaryocyte may shed - to - platelets
2000-4000
maturation sequence of megakaryoblast to platelets is about - days
5-7 days
in differentiating the maturation stages of the megakaryocytic cells, emphasis should be placed on the -
cytoplasmic appearance
stage -
megakaryoblast
1
stage -
promegakaryocyte (basophilic megakaryocyte)
2
stage -
granular megakaryocyte
3
stage -
mature megakaryocyte
4
stage -
SHAPE: round oval/ kidney shaped
1
stage -
SHAPE: irregular, horseshoe shape
2
stage -
SHAPE: multiple nuclei or multilobed
4
stage -
chromatin: fine
1
stage -
chromatin: coarse
2
stage -
chromatin: coarse and linear
4
stage -
nucleoli: multiple nucleoli
1,2
stage -
nucleoli: no nucleoli visible
3,4
stage -
cytoplasm: deeply basophililc, darker than myeloblast
1
stage -
cytoplasm: less basophilic
2
stage -
cytoplasm: pinkish blue
3
stage -
cytoplasm: totally pink
4
stage -
granules: nongranular/rare
1
stage -
granules: granules begin to form in golgi region
2
stage -
granules: very fine and diffusely granular
3
stage -
granules: coarse clumps of granules aggregating into little bundles, which BUD OFF from the peiphery to become platelets
4
stage -
n/c ratio: 10:1
1
stage -
n/c ratio: 4:1-7:1
2
stage -
n/c ratio: 2:1-1:1
3
stage -
n/c ratio: less than 1:1
4
there are - terminal megakaryocyte differentiation stages
3
Terminal
megakaryoblast
MK I
Terminal
promegakaryocyte
MK II
Terminal
megakaryocyte
MK III
Terminal
platelets
none