PLATELET

Question 1

Platelet Function Tests

Answer 1

Bleeding time
Capillary Fragility Test
Clot Retraction Time

Question 2

Coagulation Studies

Answer 2

Clotting Time ( Slide and Tube)
PT
APTT

Question 3

Primary hemostasis:

Answer 3

platelets

Question 4

Secondary hemostasis:

Answer 4

Coagulation factors

Question 5

process of forming barrier to blood loss and maintain blood in the fluid state

Answer 5

coagulation/hemostasis

Question 6

2 Stages of Hemostasis:

Answer 6

Primary Hemostasis

Secondary Hemostasis

Question 7

involves the formation of “platelet plug”

blood cells involved: ______

Answer 7

primary hemostasis

platelets & vascular system

Question 8

formation of “stable fibrin clot”

blood cells involved: _____

Answer 8

secondary hemostasis

coagulation factors

Question 9

the ability to constrict to prevent blood loss

Answer 9

vascular system

[components aside from platelets in primary hemostasis]

Question 10

3 events that occur during primary hemostasis:

Answer 10

vasoconstriction
platelet adhesion
platelet aggregation

Question 11

Not considered as cells; just fragments of the cytoplasm of megakaryocytes

Answer 11

platelets

Question 12

where is coagulation factors come from?

Answer 12

plasma

Question 13

Coagulation factors:

reinforce the plug made during primary hemostasis; not yet stable

Answer 13

Activated/Factor I - Fibrinogen

Question 14

What coagulation factor stabilizes the plug?

Answer 14

Activated factor XIII

Question 15

lysis of fibrin clot after the damaged sub endothelial tissue is complexly sealed and healed

Answer 15

Fibrinolysis

Question 16

prevents obstruction of the flow of the blood

Answer 16

fibrinolysis

Question 17

In fibrinolysis:
Plasminogen is converted into ______ because it will degrade the stable fibrin clot that is produced by coagulation factors in the secondary hemostasis

Answer 17

plasmin

Question 18

physiologic process that removes insoluble fibrin deposits by enzymatic digestion of the stabilized fibrin polymers

Answer 18

Fibrinolysis

Question 19

overview of the events during fibrinolysis:

Answer 19

1. Plasminogen activator is released
2. Conversion of plasminogen into plasmin
3. Plasmin converts fibrin to fibrin degradation product

Question 20

Disk-shape cells; measuring ______

Answer 20

0.5 to 3.0 um

Question 21

Normal value:

Answer 21

150,000 - 400,000/cumm

Question 22

Life span:

Answer 22

7 to 10 days

Question 23

platelets are formed from the cytoplasm of megakaryocytes in the ______

Answer 23

bone marrow

Question 24

In order to determine the concentration of platelets in the whole blood

Platelet count:

Answer 24

Wright’s stained blood smear (estimation of platelets)
Haemocytometer
Electronic cell counter

Question 25

provides the estimation of platelet number, size, and distribution of platelets in the peripheral blood smear

Answer 25

Wright's stained blood smear

Question 26

Platelet development:

Answer 26

- Synthesized in the bone marrow as undergo megakaryopoiesis - megakaryoblast, the mother cell, undergo development - until produce megakaryocytes (parent cell) - then undergo fragmentation of cytoplasm of the megakaryocytes - then become the platelets

Question 27

Parent cell

Answer 27

megakaryocytes (80 to 150 um)

Question 28

Platelet is stimulated in ______/ regulates the production of platelet

Answer 28

thrombopoietin

Question 29

Distribution of platelets: | 80% of platelets is located in _______

Answer 29

peripheral circulation

Question 30

20% of platelets is located in _______

Answer 30

spleen

Question 31

the platelet of peripheral circulation is LOW, while the platelet of spleen is HIGH. what is the condition of the patient?

Answer 31

thrombocytopenic

Question 32

if a patient has undergo splenectomy, 100% of platelets are in the peripheral circulation. what is the condition of the patient?

Answer 32

thrombocytosis

Question 33

without spleen?

Answer 33

thrombocytosis

Question 34

if there is splenomegaly?

Answer 34

thrombocytopenia

Question 35

Platelet granules:

Answer 35

alpha granules and dense granules

Question 36

Components of Alpha granules:

Answer 36

the fibrinogen and platelet derived growth factor (PDGF); Von-Willebrand factor (VWE), B-thromboglobulin, thrombospondin, fibronectin, platelet albumin

Question 37

non-protein factors granules

Answer 37

Dense granules

Question 38

contact promoting factor granules

Answer 38

Alpha granules

Question 39

Non-protein factors:

Answer 39

Adenosine diphosphate [ADP] Adenosine triphosphate [ATP] 5-hydroxytryptamine/serotonin Calcium

Question 40

Functions of each: Adenosine diphosphate [ADP] Adenosine triphosphate [ATP] 5-hydroxytryptamine/serotonin Calcium

Answer 40

ADP - stimulate platelet aggregation ATP - source of energy 5HT - vasoconstrictor CALCIUM - designated as coagulation factor no. 4

Question 41

Platelet Ultrastructure:

Answer 41

``` Glycocalyx Microtubule & Microfilament Open canalicular system Dense tubular system Mitochondria Glycogen granules Alpha granules Dense granules ```

Question 42

Outer membrane of platelet surface; rich in glycoproteins and serve as a membrane receptors

Answer 42

glycocalyx

Question 43

What are the glycoproteins?

Answer 43

Gp Ib, Gp IIb, GpIIIa, Gp Va

Question 44

a glycoprotein that is the receptor site for Von-Willebrand factor (VWE) in the presence of ristocetin

Answer 44

Gp Ib

Question 45

a glycoproteins that act as receptors for VWF and fibrinogen

Answer 45

Gp IIb together with Gp IIIa

Question 46

receptor for thrombin that activates fibrinogen forming fibrin

Answer 46

Gp Va

Question 47

Provides an active means of platelet contraction to squeeze out contents of cytoplasmic granules

Answer 47

microtubule and microfilament

Question 48

form as sub membranous bond around the circumference of the cell and structurally support the normal discoid shape of platelets

Answer 48

Microtubules

Question 49

contain actin and closely related to microtubules

Answer 49

microfilaments/thrombosthenin

Question 50

provides a direct communication between the intracellular and extracellular compartments

Answer 50

open canalicular system

Question 51

- forms a circle within the microtubule - serve as a site for arachidonic acid metabolism - function as calcium-sequencing pump that maintains platelet cytoplasmic level.

Answer 51

dense tubular system

Question 52

responsible for energy production

Answer 52

mitochondria

Question 53

provide energy substrate

Answer 53

glycogen granules

Question 54

Platelet Function:

Answer 54

``` Damaged subendothelium Tissue platelet activators Plug formation Growth-limiting factors of the platelet aggregate Granular release ```

Question 55

Function: | Releases factors that will activate, transform its shape and evolve as a sticky platelet aggregate to form a plug.

Answer 55

damaged subendothelium

Question 56

Factors involved in damaged subendothelium:

Answer 56

collagen, fibronectin, VWF, thrombin, ADT

Question 57

Cause the platelet to change from discoid to spherical and the dense and Alpha granules undergo internal contraction and decentralization. This process is calcium dependent.

Answer 57

tissue platelet activators

Question 58

stimulated by thrombin and thromboxane [TXA2]

Answer 58

plug formation

Question 59

blood flow and release of prostaglandin

Answer 59

growth-limiting factors of the platelet aggregate

Question 60

release of substances from dense granules such as serotonin, prostaglandins, except for TXA2. Also release of lysozymes which causes local inflammation and vasodilation.

Answer 60

granular release

Question 61

The development of megakaryopoiesis which occurs by endomytosis (nuclear splitting without cell division)

Answer 61

Platelet kinetics

Question 62

A single megakaryoblast contain 2-64x the number of normal chromosomes

Answer 62

megakaryoblast

Question 63

Stages of Megakaryocytic Maturation:

Answer 63

Megakaryoblast Promegakaryocyte Granular megakaryocyte Mature megakaryocyte

Question 64

Megakaryoblast ``` Size range: Cytoplasmic staining: Granules: Nuclear morphology: N:C ratio: ```

Answer 64

``` Size range: 0-24um Cytoplasmic staining: deep blue staining Granules: rare Nuclear morphology: few compacted lobes N:C ratio: high ```

Question 65

Promegakaryocyte ``` Size range: Cytoplasmic staining: Granules: Nuclear morphology: N:C ratio: ```

Answer 65

Size range: 14-30 um Cytoplasmic staining: basophilic with pink center Granules: few Nuclear morphology: lobes spread out in horseshoe shape N:C ratio: moderate

Question 66

Granular megakaryocyte ``` Size range: Cytoplasmic staining: Granules: Nuclear morphology: N:C ratio: ```

Answer 66

``` Size range: 15 - 56 um Cytoplasmic staining: mostly pink Granules: extensive Nuclear morphology: many lobes spread out N:C ratio: moderate ```

Question 67

Mature megakayocyte ``` Size range: Cytoplasmic staining: Granules: Nuclear morphology: N:C ratio: ```

Answer 67

``` Size range: 20-50 um Cytoplasmic staining: totally pink Granules: organized into platelet fields Nuclear morphology: many compacted lobes N:C ratio: low ```

Question 68

The purpose of diluting fluid is to ______

Answer 68

to prevent adhesion of platelets to the glass surface

Question 69

The purpose of discarding 2-3 drops _______

Answer 69

so that the mixture inside the bulb will go down to the long stem, otherwise kung modiretso ra mog charge, ang inyo macharge ninyo sa hemocytometer is purely diluting fluid so di ka makakita og cell so mao kinahanglan mag discard og 2-3 drops

Question 70

In Direct platelet count (Rees-Ecker Method), the purpose of 10 minutes ________

Answer 70

is to allow settling of the platelets na mastable sila.

Question 70

In Direct platelet count (Rees-Ecker Method), the purpose of 10 minutes ________

Answer 70

is to allow settling of the platelets na mastable sila.