MTAP W4 (Hematology: Checkpoint notes: Megakaryopoiesis/Platelets) Flashcards
1
Q
fragments of the cytoplasm of mature megakaryocytes
A
platelets
2
Q
progenitor cell of megakaryocytopoiesis/thrombopoiesis
A
CFU-GEMM
3
Q
3 stages of megakayocytes lineage-committed progenitor cells
least mature; clones hundreds of daughter cells
A
BFU-Meg
4
Q
3 stages of megakayocytes lineage-committed progenitor cells
intermediate; clones scores of daughter cells
A
CFU-Meg
5
Q
3 stages of megakayocytes lineage-committed progenitor cells
more mature; undergoes first stage of endomitosis
A
LD-CFU-Meg
6
Q
influence proliferation of the stem and progenitor cells
A
- SCF/stem cell factor
- IL-3
- GM-CSF
7
Q
support megakaryocyte production, primarily maturation
A
- IL-6
- IL-11
8
Q
major humoral factor regulating platelet development which influences all stage of megakaryocyte production
A
thrombopoietin
9
Q
the development of megakaryocytes
nuclear division without cytoplasmic division
A
endomitosis
10
Q
a single megakaryocyte may shed - to - platelets
A
2000-4000
11
Q
maturation sequence of megakaryoblast to platelets is about - days
A
5-7 days
12
Q
in differentiating the maturation stages of the megakaryocytic cells, emphasis should be placed on the -
A
cytoplasmic appearance
13
Q
stage -
megakaryoblast
A
1
14
Q
stage -
promegakaryocyte (basophilic megakaryocyte)
A
2
15
Q
stage -
granular megakaryocyte
A
3
16
Q
stage -
mature megakaryocyte
A
4
17
Q
stage -
SHAPE: round oval/ kidney shaped
A
1
18
Q
stage -
SHAPE: irregular, horseshoe shape
A
2
19
Q
stage -
SHAPE: multiple nuclei or multilobed
A
4
20
Q
stage -
chromatin: fine
A
1
21
Q
stage -
chromatin: coarse
A
2
22
Q
stage -
chromatin: coarse and linear
A
4
23
Q
stage -
nucleoli: multiple nucleoli
A
1,2
24
Q
stage -
nucleoli: no nucleoli visible
A
3,4
25
stage -
cytoplasm: deeply basophililc, darker than myeloblast
1
26
stage -
cytoplasm: less basophilic
2
27
stage -
cytoplasm: pinkish blue
3
28
stage -
cytoplasm: totally pink
4
29
stage -
granules: nongranular/rare
1
30
stage -
granules: granules begin to form in golgi region
2
31
stage -
granules: very fine and diffusely granular
3
32
stage -
granules: coarse clumps of granules aggregating into little bundles, which BUD OFF from the peiphery to become platelets
4
33
stage -
n/c ratio: 10:1
1
34
stage -
n/c ratio: 4:1-7:1
2
35
stage -
n/c ratio: 2:1-1:1
3
36
stage -
n/c ratio: less than 1:1
4
37
there are - terminal megakaryocyte differentiation stages
3
38
Terminal
megakaryoblast
MK I
39
Terminal
promegakaryocyte
MK II
40
Terminal
megakaryocyte
MK III
41
Terminal
platelets
none
42
megakaryocytopoiesis stage:
first recognizable stage in megakaryocytic series
megakaryoblast
43
megakaryocytopoiesis stage:
with HORSE-SHOE shaped nucleus
promegakaryocyte
44
megakaryocytopoiesis stage:
platelet shedding; largest cell in the BM
mature megakaryocyte
45
megakaryocytopoiesis stage:
Demarcation membrane system develops
MK 1 (rodaks), MK2/promegakaryocyte (steininger, mckenzie)
46
internal membrane system of channels derived by invagination of the megakaryocyte's outer membrane
demarcation membrane system
47
- are believed to pierce through or between sinusoid-lining endothelial cells, etend into the venous blood and shed platelets
proplatelet processes
48
fourth stage of magakaryocyte maturation
metamegakaryocyte
49
was previosluy reffered to as megakaryocyte stage with platelet shedding
megakaryocyte
50
biconvex, disc-shaped, ANUCLEATE cell fragments with smooth surfaces
platelets/thrombocytes
51
tends to 'ROUND UP' in an EDTA
platelets/thrombocytes
52
size:1-4um
irregular, lavander and granular on wright stained smear
platelets/thrombocytes
53
platelets/thrombocytes
sytoplasmic parts: granular and located centrally
chromomere
54
platelets/thrombocytes
sytoplasmic parts: surrounds the chromomere, nongranular and clear to light blue
hyalomere
55
appear in compensation for thrombocytopenia
reticulated platelets/ stress platelets
56
larger (6um) than ordinary, potentially PROTHROMBOTIC associated with increased risk of cardiovascular disease
reticulated platelets/ stress platelts
57
platelets in
-: round up
EDTA
58
platelets in
-: cylindrical and beaded resembling fragment of megakaryocyte
citrate
59
platelet life span
7-10 days (rodals)
9-12 days
60
circulating platelets are distributed between the (2)
spleen and blood
61
circulating platelets
= in the spleen
1/3
62
circulating platelets
=peripheral blood
2/3
63
platelet count is - in px without a spleen
higher
64
platelet count is - in px with splenomegaly
low
65
platelets are removed by - in the liver and spleen
macrophage
66
platelets are removed by macrophage. platelet turnover rate is - each day
35,000/uL
67
perfom surveillance of blood vessel continuity, aid in healing injured tissue
platelet
68
platelet function: -
platelet-platelet interaction
primary hemostatic plug
69
platelet function: -
platelet-coagulation protein interaction
secondary hemostatic plug
70
composed of:
60% protein
30% lipid
8% carbohydrate
platelet
71
platelet structure: divided anatmoically into 4 areas
1. peripheral zone
2. sol-gel zone
3. organelle zone
4. membranous system
72
platelet structure: -
composed of membranes and responsible for PLATELET ADHESION AND AGGREGATION
peripheral zone
73
platelet structure: peripheral zone includes
1. glycocalyx/surface coat
2. plasma membrane
3. submembranous area
74
platelet structure: peripheral zone
outer surface composed of coagulation factors V, VIII and fibrinogen (58F)
glycocalyx/surface coat
75
platelet structure: peripheral zone
important in platelet reaction with thrombin, VWF and fibrinogen
glycocalyx/surface coat
76
platelet structure: peripheral zone
provides surface for coagulation factors I,V,VIII, X, XI, XII, XIII (1,5,8,10,11,12,13)
glycocalyx/surface coat
77
platelet structure: peripheral zone
lies directly beneath the glycocalyx and is composed of phospholipid bilayer with integral proteins imbedded
plasma membrane
78
platelet structure: peripheral zone
consists of 30 or more glycoproteins, phopholipids, and platelet VIII:vWF
plasma membrane
79
platelet structure: peripheral zone
messages from external membrane are translated into chemical signals causing activation and a physical change in the platelet
submembranous area
80
platelet structure: peripheral zone
glycoprotein receptors
receptor for VWF
glycoprotein Ib
81
platelet structure: peripheral zone
glycoprotein receptors
noncovalently associated with GPIX and GPV in the membrane (2:2:1 ratio)
glycoprotein Ib
82
platelet structure: peripheral zone
glycoprotein receptors
aka CD42
glycoprotein Ib
83
platelet structure: peripheral zone
glycoprotein receptors
receptor for fibrinogen
glycoprotein IIb/IIIa
84
platelet structure: peripheral zone
glycoprotein receptors
integrin CD41/CD61
glycoprotein IIb,IIIa
85
platelet structure: peripheral zone
glycoprotein receptors
receptor for thrombin
glycoprotein V
86
platelet structure: -
lies directly beneath the platelet membrane and provides cytoskeleton to maintain platelet shape and contractile system
sol-gel zone/structural zone
87
platelet structure: sol-gel zone/structural zone
contains 2 structures
microfilaments, microtubules
88
platelet structure: sol-gel zone/structural zone
forms ACTOMYSIN or THROMBOSTHENIN upon platelet activation
actin and myosin
89
platelet structure: sol-gel zone/structural zone
responsible for CLOT RETRACTION
15% of all proteins in platelets
actin and myosin
90
platelet structure: sol-gel zone/structural zone
maintains platelet's DISC SHAPE
tubulin
91
platelet structure: organelle zone
- granules: calcium, ADP, ATP, Serotonin/5-hydroxytryptamine, magnesium, pyrophosphate
dense granules
92
platelet structure: organelle zone
for ATP synthesis for platelet metabolism
mitochondria
93
platelet structure: membranous system
2 systems
1. dense tubular system
2. open canalicular system
94
platelet structure: membranous system
serves as the site of ARACHIDONIC ACID metabolism
dense tubular system
95
platelet structure: membranous system
derived from smooth ER
holds CALCIUM-SEUQESTERING PUMP for platelet activation processes
dense tubular system
96
platelet structure: membranous system
'CONTROL CENTER' for platelet activation
contains enzymes that support PROSTAGLANDIN synthesis
dense tubular system
97
platelet structure: membranous system
production of TXA2 (eicosanoid synthesis pathway)
dense tubular system
98
platelet structure: membranous system
production of INOSITOL TRUPHOSPHATE/IP3 and diacylglycerol/DAG
dense tubular system
99
platelet structure: membranous system
TXA2/EICOSANOID SYNTHESIS PATHWAY uses enzymes
1. phospholipase A2
2. cyclooxygenase
3. thromboxane synthetase
100
platelet structure: membranous system
IP3 and DAG eznyme
phospholipase C
101
platelet structure: membranous system
RELEASE OF GRANULES
open canalicular system/surface connecting system
102
platelet structure: membranous system
invagination of the plasma membrane
open canalicular system/surface connecting system
103
platelet structure: membranous system
provides direct communication between intracellular and extracellular compartments
open canalicular system/surface connecting system
