CHAPTER 1 - HEMOSTASIS PART 4 Flashcards
- resemble myeloblast and pronormoblast.
A. Megakaryoblast
- Cytoplasm is abundant, with minimal lobularity
B. Promegakaryocyte
-nucleus is lobulated and basophilic.
C.Megakaryocyte
Cytoplasm is granular and azurophilic.
C.Megakaryocyte
With DMS
C.Megakaryocyte
: future platelet
D. Metamegakaryocyte
Nucleus* MK-I (Megakaryoblast)
Round
Nucleus* MK-II (Promegakaryocyte)
Indented
Nucleus* MK-III (Megakaryocyte)
Multilobed
Chromatin* MK-I (Megakaryoblast)
Homogenous
Chromatin* MK-II (Promegakaryocyte)
Chromatin* MK-III(Megakaryocyte)
Deeply and variably condensed
Endomitosis* MK-I (Megakaryoblast)
Endomitosis* MK-II (Promegakaryocyte)
Endomitosis* MK-III(Megakaryocyte)
Demarcation system Present (Rodak’s)
MK-I (Megakaryoblast)
MK-II (Promegakaryocyte)
MK-III(Megakaryocyte)
Demarcation system Present (Steininger)
MK-III(Megakaryocyte)
20
MK-I (Megakaryoblast)
25
MK-II (Promegakaryocyte)
55
MK-III(Megakaryocyte)
14—18 mm
MK-I (Megakaryoblast)
15—40 mm
MK-II (Promegakaryocyte)
30—50 mm
MK-III(Megakaryocyte)
2—6
MK-I (Megakaryoblast)
Variable
MK-II (Promegakaryocyte)
Not visible
MK-III(Megakaryocyte)
3:1
MK-I (Megakaryoblast)
1:2
MK-II (Promegakaryocyte)
1:4
MK-III(Megakaryocyte)
Mitosis Absent
MK-I (Megakaryoblast)
MK-II (Promegakaryocyte)
MK-III(Megakaryocyte)
Basophilic
MK-I (Megakaryoblast)
Basophilic and granular
MK-II (Promegakaryocyte)
Azurophilic and granular
MK-III(Megakaryocyte)
a-Granules Present
MK-I (Megakaryoblast)
MK-II (Promegakaryocyte)
MK-III(Megakaryocyte)
Dense granules Present
MK-I (Megakaryoblast)
MK-II (Promegakaryocyte)
MK-III(Megakaryocyte)
Platelets- originated from
megakaryocyte cytoplasm
Platelets Characteristics:
-Granular cytoplasm
-No nuclear material
-Size:
2-4 um (2.5 um)
Types of platelets:
RESTING PLATELET
STRESS PLATELET
-MPV:
7 fL (8-10 fL)
-Lifespan:
9-10 days (8-11 days)
-Normal count:
150450x10^9/L (150-400)
Normally biconvex
RESTING PLATELET
Markedly larger than normal platelet
STRESS PLATELET
RESTING PLATELET EDTA:
round
RESTING PLATELET Wright stained smear:
circular/irregular
STRESS PLATELET EDTA:
round
STRESS PLATELET Citrated blood:
cylindrical (pencil-shape) or beaded
STRESS PLATELET MPV:
> 6 um; 12to 14 fL
Flow smoothly in veins
RESTING PLATELET
Carry ribosomes and fragment of RER
STRESS PLATELET
It moves back and forth from venules to the white pulp (sequestration)
RESTING PLATELET
Comes from rapid proplatelet extension and release
STRESS PLATELET
**Sequestered platelet
RESTING PLATELET
***Prothrombic
STRESS PLATELET
-Primary Hemostasis-
maintain vascular integrity
-Secondary Hemostasis-
participates in blood coagulation.
I. Peripheral Zone- contains
Glycocalyx, Plasma Membrane and Submembrane area
a) Glycocalyx
-Gp [?]
la,lIb,Ic, lla, lIb,IlI, IV and V
a) Glycocalyx
-Surface for the adherence of CF:
I,V, VII, XI, XII, XIII
a) Glycocalyx
-VWF:[?]
VIII
- underlies the plasma membrane; receives message from outside
Il. Submembrane Area
- underlies the submembrane filaments
IlI. Sol-Gel Zone
contractile force after activation of platelets
a) Microtubules:
cytoskeleton
b) Microfilaments:
communication of the organelles
c) Sol gel stable gel component:
IV. Organelle Zone: (Refer to page 14/93 of your module)
V. Membrane System:
-Open Canalicular System
-Dense Tubular System
: for external communication
-Open Canalicular System
: for arachidonic synthesis
-Dense Tubular System
HMWK
Alpha
Fibrinogen
Alpha
Factor V and VIll:wWE
Alpha
Thrombospond
Alpha
PF4
Alpha
Beta thromboglobulin
Alpha
PDGF
Alpha
Plasminogen and a-2 antiplasmin
Alpha
C1 esterase inhibitor
Alpha
ADP
Dense
АТР
Dense
Calcium
Dense
Magnesium
Dense
Serotonin
Dense
-adheres to detached/injured endothelium
Adhesion
- shape change
Platelet Release Reaction
-Alpha and Dense granules release substances
Platelet Release Reaction
Platelet aggregation -
Glycoprotein and Fibrinogen
Vasoconstriction-
serotonin
Clot formation-
PF3
PLATELETS - originated from megakaryocyte cytoplasm thru
platelet shedding or thrombopoiesis
More specific for plt production
thrombopoiesis
: acts on megakaryocyte to shed off platelet
thrombopoietin
stimulated BM to roduce megakaryocyte; induces production and proliferation
thrombopoietin
thrombopoietin targets
megakaryocyte and platelet
needed to shed off platelet
growth factors/cytokines
: induces plt shedding
Interleukin 3, 6, 11
is not automatic
shedding of cytoplasm
[?] is released in the circulation → sequestered in the [?] due to small arterioles → megakaryocyte proceed to the smallest one allowing only [?] to pass thru leaving the cytoplasm → cytoplasm gets perforated by macrophage to divide into small pieces that becomes the [?]
megakaryocyte
spleen
nucleus
platelet
– production of megakaryocyte
Megakaryopoiesis
: no granules yet (starts w/ promyelocyte)
Myeloblast
primary granules -
promyelocyte
secondary -
myelocyte
tertiary -
metamyelocyte
- none yet
pronormoblast
all look the same in al blasts
size, appearance and cytoplasm
is distinguishable from myeloblast and pronormoblast in terms of size (more cytoplasm)
Promegakaryocyte
Megakaryocyte
[?] stage (Rodaks); [?] (Steininger)
Last and final
third
Produces platelet (Rodaks)
Megakaryocyte
Produces platelet (Steininger)
Metamegakaryocyte
has a demarcation system
Megakaryocyte
: extension of platelet; marks the boundary of a true cytoplasm from an extension cytoplasm
demarcation system
Not all produces platelet. Not because of long DMS or large cytoplasm but because it must have
at least 4 nuclei
there is already a complete DMS where future platelet are derived from
Platelet comes from the DMS
Metamegakaryocyte
2 organelles/component of platelet:
mitochondria and granules
does not have a nuclues (not true blood cell)
platelet
one of the most fxnal blood cell in the body
platelet
Diseases of large platelet:
[?] has higher plt ct – [?] are born with faster plt production
Women
woman
men:
122 to 350
women:
140 to 379
Men has higher rbc – woman has [?] that inhibits erythropoiesis
estrogen
• Diameter
2 - 4 um (range) 2.5 um (average)
• MPV (Mean Platelet Volume)
8 - 10 fL (range): Actual
2 - 20 fL: Automated
7 fL (average) ): Actual
• Reference platelet count
150,000 - 450,000/pL (Steininger)
150,000 - 400,000/pL (Rodak’s)*
• Daily turnover
35 X 10%/L (+/- 43)
• Lifespan
8 - 11 days
9 - 10 days (Rodak’s)*
• Function
maintenance of vascular integrity and blood coagulation
Circulating or Peripheral platelet
RESTING PLATELET
– seen in blood smear
Circulating or Peripheral platelet
(1D – other side can be seen)
EDTA: round
(2D)
Wright stained smear: circular/irregular
Normally biconvex
RESTING PLATELET
Flow smoothly in veins
RESTING PLATELET
It moves back and forth from venules to the white pulp (sequestration)
RESTING PLATELET
:Some plt are found in the speel and not circulating, otherwise, prothrombic (may clot)
Sequestered platelet
Circulating:
2/3
Spleen: sequestered in the spleen
1/3 (30%)
Hides and used up during bleeding
Sequestered platelet
Occurs in injury, inflammation, and surgeries
Sequestered platelet
Markedly larger than normal platelet
STRESS PLATELET
Reticulated platelet
STRESS PLATELET
– forced by BM to mature when needed
Reticulated platelet
Carry ribosomes and fragment of RER like rbc from megakaryocyte
STRESS PLATELET
Comes from rapid proplatelet extension and release
STRESS PLATELET
More clots are produced when released to the circulation sinceit is very reactive
Prothrombic
accumulated/occluded clot may proceed to the brain or heart
Prothrombic
px is prone to cardiovascular disease
Prothrombic
Occurs in thrombocytopenia
Prothrombic
Lines the endothelium
Primary Hemostasis
Provides phospholipid membrane
Secondary Hemostasis
– assembly area of coagulation (Plt FIII)
phospholipid membrane
outer portio
Glycocalyx
thicker than cytoplasma of rbc and wbc has the F III
Glycocalyx
surface for the adherence of CF
Glycocalyx
serves as a surface coat and has a very thick (than rbc) and dense (than wbc) charac
Glycocalyx
: imp for adherence and aggregation
Gp Ia, Ib,Ic, IIa, lIb, III, IV and V
: adhesion
Ib-IX-V complex
o P1 selectin
o MAC 1
: agggregation
IIb-IIa
Surface for the adherence of CF:
I,V,VII, XI, XII, XIII
used glycocalyx of platelet as surface adherence area
I,V,VII, XI, XII, XIII
VWF: VIII - one complex
: imp for platelet
: imp for coagulation
VWF
VIII
underlies the plasma membrane; receives message from outside
Submembrane Area
underlies the submembrane filaments
Sol-Gel Zone
shape change denotes inactivation due to:
a) Microtubules
b) Microfilaments
c) Sol gel stable gel component
: contractile force after activation of platelets
a) Microtubules
: cytoskeleton
b) Microfilaments
– exists in the muscle
actin and myosin : actomyosin
– exists in the platelet
thrombostenin
: communication of the organelles
Sol gel stable gel component
regulates arrangement of organelles
Sol gel stable gel component
: responsible for shape change
Microtubules and Microfilaments
supports discoid shape of plt
Microtubules and Microfilaments
Membrane System
-Open Canalicular System
-Dense Tubular System
: for external communication
-Open Canalicular System
: for arachidonic synthesis
-Dense Tubular System
CAMPAS
Calcium – ATP – Magnesium – Phosphate ADP – Serotonin
First four promotes aggregation
Calcium – ATP – Magnesium – Phosphate
Physical Properties and Functions of Platelets
- Adhesion
- Platelet Release Reaction
- Platelet aggregation
Platelets adhere only on detached or injured Endothelium
Adhesion
Requires plasma von Willebrand Factor & Gp Ib-IX complex
Adhesion
Platelet undergoes shape change.
Platelet Release Reaction
Alpha & dense granules release substances that will contribute to platelet aggregation and activation of the coagulation system
Platelet Release Reaction
Requires Gp IIb-IIIa and plasma fibrinogen
Platelet aggregation
Other functions
- Vasoconstriction
- Clot formation
Enhanced by serotonin released from platelets
- Vasoconstriction
Platelet factor 3 is needed for the formation of active plasma thromboplastin
- Clot formation
A lipoprotein (phospholipid) found in platelet granules & membrane and required in 2 steps of the coagulation process
PF3*
A glycoprotein stored in the alpha granules and is extruded during the platelet release reaction
PF4*
aids in ADP-induced platelet aggregation and inhibits effect of heparin
PF4*
Plasma coagulation factor V
PF1
A globulin that inhibits antithrombin III
PF2
increases platelet aggregation and accelerates interaction of thrombin and fibrinogen (fibrinoplastic platelet factor)
PF2
Platelet fibrinogen
PF 5
A plasma inhibitor associated with platelets
PF6
Cothromboplastin
PF7
Antithromboplastin factor
PF8
Accelerator globulin stabilizing factor
PF9
Serotonin found in the dense granules
PF 10
Promote coagulation
Alpha granules
Promote aggregation
Dense bodies
Alpha granules
Promote vasoconstriction
Dense bodies
Membrane phospholipids
Promote vascular repair
Alpha granules
Other systems
Alpha granules
Contact activation of intrinsic coagulation pathway
HMWK
Converted to fibrin for clot formation
Fibrinogen
Cofactor in fibrin clot formation
Factor V
Assists platelet adhesion to subendothelium to provide coagulation surface
Von Willebrand factor
Promotes vasoconstriction at injury site
Serotonin
Thromboaxane A2 precursors
Promotes smooth muscle growth
Platelet-derived growth factor
Chemotactic for fibroblasts
Beta- thromboglobulin
Precursor to plasmin, which induces clot affected
Plasminogen
Plasmin inhibitor; inhibits clot lysis
a-2 – antiplasmin
Complement system inhibitor
C1 esterase inhibitor
Alpha granules
HMWK
Fibrinogen
Factor V
Von Willebrand factor
Platelet factor 4
Thrombospondin
Platelet-derived growth factor
Plasminogen
a-2 – antiplasmin
C1 esterase inhibitor
Dense bodies
ADP
Calcium
Serotonin
Membra ne phosphol ipids
Thromboaxane
A2 precursors
Promote coagulation
HMWK
Fibrinogen
Factor V
Von Willebrand factor
Promote aggregation
ADP
Calcium
Platelet factor 4
Thrombospondin
HMWK
Promote coagulation
Fibrinogen
Promote coagulation
Factor V
Promote coagulation
Von Willebrand factor
Promote coagulation
ADP
Promote aggregation
Calcium
Promote aggregation
Platelet factor 4
Promote aggregation
Thrombospondin
Promote aggregation
Serotonin
Promote vasoconstri ction
Thromboaxane A2 precursors
Promote vasoconstri ction
Platelet-derived growth factor
Promote vascular repair
Beta- thromboglobulin
Promote vascular repair
Other systems
Plasminogen
a-2 – antiplasmin
C1 esterase inhibitor
A lipoprotein (phospholipid) found in platelet granules & membrane
PF3*
required in 2 steps of the coagulation process
PF3*
A glycoprotein stored in the alpha granules
PF4*
aids in ADP-induced platelet aggregation
PF4*
extruded during the platelet release reaction
PF4*
inhibits effect of heparin
PF4*
Platelet fibrinogen
PF 5
A plasma inhibitor associated with platelets
PF6
Cothromboplastin
PF7
Antithromboplastin factor
PF8
Accelerator globulin stabilizing factor
PF9
Serotonin found in the dense granules
PF 10
Plasma coagulation factor V
PF1
A globulin that inhibits antithrombin III
PF2
increases platelet aggregation and accelerates interaction of thrombin and fibrinogen
PF2
fibrinoplastic platelet factor
PF2
