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Flashcards in Vascular Part 1 Deck (39):
1

State five reasons why a thrombus does not normally form in intact vessels.

-Smooth surface
-Prostacyclin
-heparan sulfate
-tissue factor pathway inhibitor (TFPI)
-Thrombomodulin

2

Platelete activation inhibitor

Prostacyclin

3

Activates antithrombin

Heparan sulfate

4

Inactivates VIIa...controls TF/extrinsic pathway

TFPI- Tissue factor pathway inhibitor

5

Activates protein C pathway

Thrombomodulin

6

State four procoagulant properties of the vascular intima that lend to thrombus formation during vascular damage.

- Vasoconstriction
-Basement membrane exposes collagen
-von Willebrand factor secreted
-Tissue factor exposed

7

Necessary for platelets to adhere to subendothelial collagen in arterioles; (and eventual) platelet aggregation.

von Willebrand factor secreted

8

Activates plasma coagulation system (factor VII)

Tissue factor exposed

9

Discuss thrombopoiesis:
List the four stages of maturation.

- Megakaryoblast
-promegakaryocyte
-megakaryocyte
-platelets (thrombocytes)

10

Nucleus round; 2-6 nucleoli; chromatin is homogeneous, loosely organized; cystoplasm basophilic

Megakaryoblast

11

Nucleus indented; nucleoli are variable; chromatin is condensed and cytoplasm is basophilic

Promegakaryocyte

12

Nucleus-2-32 lobes (8 lobes are most common); cytoplasm is blue to pink and abundant; granules reddish blue.

Megakaryocyte

13

No nucleus; light blue to colorless cytoplasm; red to violet, abundant granules.

Platelet (thrombocytes)

14

Regulatory mechanism of thrombopoiesis.

Growth factor, specifically hormone called thrombopoietin

15

Sites of platelet production

Medullary=BM; extramedullary=lungs

16

Describe the morphology of a normal platelet when stained with wright's stain.

chromomere aka granulomere; Hyalomere
Outside of platelets is light color and round

17

Name the two pools into which platelets are distributed

Circulatory pool (2/3) and splenic pool (1/3)

18

state the average life span of the platelet

8-12 days

19

Discuss four platelet functions.

Source of PF3
Source of PF4
Maintain vessel integrity
formation of platelet plug

20

Phospholipid found within platelet membrane and is essential reaction site in the cascade.

source of PF 3

21

Protein found in platelet's alpha granules and is capable of neutralizing heparin

Source of PF 4

22

What is the job of maintaining vessel integrity in platelet?

Platelets adhere to the subendothelial collagen, and fill in the gaps until new endothelial cells grow

23

List four causes of platelet activation caused by traumatic venipuncture and/or shaking of the sodium citrate tube

Subsequent release of PF4
PF4 will neutralize heparin in blood sample
falsely shorten APTT
potential for subsequent over anticoagulation of the paitent

24

In the formation of the platelet plug: Is it primary or secondary hemostasis?

Primary

25

In the formation of the platelet plug: does it have short or long term effect?

Short term effect

26

In the formation of the platelet plug: list two hemostatic systems involved in primary hemostasis?

Vascular intimia and Platelets

27

In the formation of the platelet plug: List type of bleeding with disorder of Primary hemostasis?

Temporarily arrests bleeding; excessive bruising & mucocutaenouse

28

In the formation of the platelet plug: type of test are used for diagnostic purposes?

Platelet tests

29

List the three steps involved in primary hemostasis.

Platelet adhesion
Platelet activation
Platelet aggregation

30

Discuss the platelet adhesion.

-Platelets first adhere to collagen
- GPIb binds platelet to vWF (bridge)
- GPIb/IX necessary to attach vWF bridge to the subendothelium for platelet adhesion

31

Discuss the platelet activation.

Platelets release procoagulant factors and synthesize prostaglandins to activate platelets

32

Discuss the platelet aggregation

Fibrinogen bridge and glycoprotein IIB/IIIa complex needed for platelets to attach to one another that is platelet aggregation

33

List three zones of platelet ultrastructure.

Peripheral zone
Sol-gel zone
Organelle Zone

34

Functions as receptor and transmitter region as well as it is essential for adhesion and aggregation.

Peripheral zone

35

Functions as cytoskeletal/contractile region.

Sol gel zone

36

Functions as metabolic/organelle region and has two types of granules.

Organelle zone

37

List two types of granules in organelle zone

Alpha and Dense bodies

38

Differentiate quantitative vs. qualitative platelet testing.

Quantitative tests-- number!!
- Platelet count or slide estimate
Qualitative Tests- Function!!
- Bleeding time, platelet function analyzer (PFA-100), platelet aggregation, clot retraction

39

Indicate why EDTA is the anticoagulant of choice when performing electronic platelets counts.

It prevents the clumping of platelets