Hema.Mod.A Lec2

Question 1

Meaning of Pancytopenia

Cause

Answer 1

Decrease in RBC, WBC, PLATELETS

Due to chemotherapy

Question 2

Meaning of Petechiae

Answer 2

Reddish purple spots

Question 3

Why does petechiae occur ?

Answer 3

Due to THROMBOCYTOPENIA (decrease in platelets)

Question 4

Primary Hemostasis is related to

Secondary Hemostasis is related to

Answer 4

Platelets

Coagulation factors

Question 5

If platelet count is down what will happen ?

Answer 5

Hemorrhage

Question 6

What happens when injury occurs (3)

Answer 6

1- Vasoconstriction

2- Primary Hemostasis (adhesion, aggregation, release reactions)

3- Secondary Hemostasis

Question 7

Beneath Endothelial Cells there are :

Endothelial cells make

Answer 7

1- Basement Membrane

2- Collagen

Lining of blood vessels

Question 8

Substances released from endothelial cells: (6)

Answer 8

1-tissue factor (initiator of coagulation)

2-VWF (carry factor 8, adhesion)

3- Nitric oxide, Prostacyclin (vasodilators, inhibit coagulation)

4- Antithrombin, Protein S, Tissue factor inhibitor (inhibit coagulation)

5- t-pa (tissue plasminogen activator)(fibrinolysis)

6- Thrombomodulin (activates protein C which inhibits coagulation)

Question 9

Protein S function

Answer 9

Helps protein C to inhibit coagulatiob

Question 10

What are platelets ?

Answer 10

Fragments of megakaryocyte cytoplasm.

Megakaryocytes are transformed to platelets by TPO

Question 11

How long does thrombopoiesis takes ?

Answer 11

10 days in BM

Question 12

t1/2 of platelets in blood:

Answer 12

10 days

Question 13

In normal state 1/3 of platelets go to

Answer 13

Spleen

Question 14

Patients with splenomegaly have

Answer 14

Low platelets

Question 15

Platelet content (2)

Answer 15

Dense granules, alpha granules

Question 16

dense granules (3)

Answer 16

Serotonin(vasoconstriction)
ADP(plat. Aggregation)
Ca2+(role in coagulation)

Question 17

alpha granules (7)

Answer 17

Fibrinogen

VWF

Factor 5

Fibronectin

B thromboglobulin

Thrombospandin

Heparin antagonist

Question 18

What is prostaglandins ?

Answer 18

Phospholipids of platelet plasma membrane

Question 19

What are the platelets functions

Answer 19

1-Adhesion
2-release reaction ( by alpha granules , dense granules)
3- aggregation ( to close wound )

Question 20

Adhesion

Answer 20

After tissue injury collagen is exposed.

platelets adhere to collagen by vWF by help of GP-1b receptor ( on platelets)

Question 21

release reaction

Answer 21

Release of :
1- Serotonin : vasoconstriction
2- ADP : aggregation
3- Prostaglandins : form TXA2 causing (vasoconstriction, ) aggregation

Question 22

platelet aggregation (done by (4), once it occurs)

Answer 22

Done by: ADP , PG , TXA2 , GPIIbIIIa
Once platelet aggregation occurs :
fibrinogen is converted to fibrin forming primary hemostatic plug

Question 23

Platelets antigens

Answer 23

1. HPA a or b = ( human platelet Antigen )
2. ABO antigens
3. HLA class I

Question 24

VWF

Answer 24

vWF is formed as multimer ( which cannot aggregate platelet )
multimers can be broken by protease into monomers and dimers , so become functional and cause platelet aggregation

Question 25

Ecchymosis

Answer 25

= bruise زرقان ( due to defect in coagulation factor genes )

Question 26

all coagulation factors are formed in liver except

Answer 26

Factor 8 and Tissue factor that are formed in endothelial cells

Question 27

PT measures

Answer 27

extrinsic pathway | If Prolonged, it's due to liver disease – low vit k

Question 28

APTT measures

Answer 28

intrinsic pathway and common pathway | If Prolonged, it's due to hemophilia , factor 11 ,12 deficiency

Question 29

An abnormal PT and a normal APTT would indicate a problem with which factor?

Answer 29

Deficiency in factor 7

Question 30

Fibrin cross links by

Answer 30

factor 8

Question 31

vit.k dependent factors

Answer 31

2,7,9,10

Question 32

factor 10a

Answer 32

stabilize fibrin

Question 33

coagulation inhibitors

Answer 33

- Tissue Factor Pathway Inhibitor (TFPI). - Anti-thrombin III. - Protein C/Protein S/Thrombomodulin (APC). - Alpha 2 macroglobulin, alpha2 antiplasmin, c1 esterase inhibitor and alpha 1 antitrypsin.

Question 34

Protein C

Answer 34

Needs protein S for its function inhibit factor 5 and 8 Thrombomodulin , thrombin cause activation of protein C result in inhibition of factor 5 and 8

Question 35

TT (thrombin time) measures:

Answer 35

fibrin formation | If Prolonged, it's due to decreased plasma fibrinogen , increased FDPs

Question 36

fibrinolysis

Answer 36

Intrinsic activation: Factor 12 activates plasminogen into plasmin Extrinsic activation: tPA activates plasminogen into plasmin Streptokinase can also activate plasminogen Plasmin converts fibrin into FDP

Question 37

inhibitors of fibrinolysis

Answer 37

PAI-1 PAI-2 (Plasminogen Activators Inhibitors) | Antiplasmin