PLATELET LEC Flashcards
small packages of cytoplasm that are nipped off from the cytoplasm of megakaryocytes
PLATELETS
nipped off from the cytoplasm of megakaryocytes through the process known as
THROMBOPOIESIS
Platelet is considered as true cell.
TRUE OR FALSE
FALSE
precursor of platelet
MEGAKARYOCYTE
4 STAGES OF MEGAKARYOPOIESIS
1.Megakaryoblast
2.Promegakaryocyte
3. Megakaryocyte
4. Metamegakaryocyte
Metamegakaryocyte
FUTURE PLATELET
resembles myeloblast and pronormoblast
MEGAKARYOBLAST
Cytoplasm is abundant, minimal lobularity
PROMEGAKARYOCYTE
most immature stage
MEGAKARYOBLAST
Nucleus is lobulated and basophilic
MEGAKARYOCYTE
Cytoplasm is granular and azurophilic with DMS
MEGAKARYOCYTE
extension of cytoplasm
DMS
COLOR PRESENT IN MEGAKARYOCYTE
DARK BLUE DEMARCATION
HORMONE INVOLED IN PLT
THROMBOPOIETIN
Nucleus of MKI
Round
Nucleus of MKII
Indented
Nucleus of MKIII
Multilobed
Chromatin of MKI
Homogenous
Chromatin of MKII
Moderately condensed
Chromatin of MKIII
Deeply and variably condensed
Endomitosis of MKI
Present
Endomitosis of MKII
Ends
Endomitosis of MKIII
Absent
SIZE of plt:
2-4 um
MPV:
7fL
Lifespan:
9-10 days
Normal count
150-450X10^9/L
Type of Platelet
a. resting platelet
b. stress platelet
resting platelet
(circulatin g platelet)
stress platelet
(reticulated platelet)
Size and shape of resting plt
Normally biconvex
Markedly larger than normal platelet >6 um
Stress platelet
MPV of stress plt
12-14 fL
Citrated blood: cylindrical
Stress plt
Wright stained smear: circular/ irregular
Resting plt
Carry ribosomes and fragments of RER
Stress plt
Flow smoothly in vein
Resting plt
direct communication with extracellular environment
Open canalicular system
site of arachidonic acid synthesis
Dense tubular system
platelet fibrinogen
PF 5
anti-heparin factor
PF 4
lipoprotein
PF 3
Inhibits antithrombin II
PF 2
Plasma coagulation factor V
PF 1
adheres to detached/injured
endothelium
Adhesion
platelet release reaction
-alpha and dense granules release substance
-shape change
glycoprotein and fibrinogen
Plt agreggation
serotonin
Vasoconstriction
clot formation:
PF3