Hemostasis

Question 1

Hemostasis

Answer 1

the prevention of blood loss and maintenance of blood flow

Question 2

vascular spasm

why this happen?

Answer 2

the reflex contraction of axial and circular smooth muscle

due to blood pressure loss & the blood flow decreases

Question 3

What will have more severe vascular spasm (sharp cut vessels or crushing vessels)?

Answer 3

sharp cut vessels

Question 4

precapillary sphincter

Answer 4

the sphincter that closes down when capillaries pressure drops below critical value

Question 5

What are the consequences of vascular spasm due to external injuries?

Answer 5

vasoconstriction of blood vessels

retraction of vessel into the surrounding tissue to protect the severe end from exposure to foreign materials

Question 6

What are the mechanisms of vasoconstriction of blood vessel in vascular spasm?

Answer 6

resulting from myogenic reflexes

local releases of vasoactive agents such as histamin, serotonin & kinin

blood loss into tissue cause local tissue pressure increase

stimulation of sympathetic nervous system

Question 7

platelets

Answer 7

the cell fragments derived from megakaryocytes in bone marrow

Question 8

What does platelets do?

Answer 8

maintaining the endothelial lining of blood vessels

repair small breaks

restricting blood flow by forming temporary platelet plug

Question 9

Process of platelet plug formation

Answer 9

adhesion

aggregation

viscous metamorphosis

Question 10

adhesion of platelets plug

Answer 10

the positive amino acids on exposed collagen fibers attract platelets to damaged vessel

Question 11

aggregation of platelets plug

Answer 11

the more attraction of platelets around injuries site

Question 12

viscous metamorphosis

Answer 12

the adhered platelets undergo morphology change in order to adhere strongly to damaged site and to each other

Question 13

What kind of morphology changes in platelets during platelets plug formation?

Answer 13

swelling &protruding spinous processes

Question 14

What are the products released during the

Answer 14

ADP + thromboxane A2

Calcium

beta-integrin

vasoactives amines

thromboplastin

platelet factor 3 (PF3)

Question 15

What do ADP + thromboxane A2 do?

Answer 15

inducer of platelet aggregation

Question 16

What does Calcium do in platelet plug formation?

Answer 16

increase the degree of platelets aggregation

Question 17

plasma coagulation

Answer 17

the formation of blood clots (permanent seal)

Question 18

beta-integrins

Answer 18

products that glue platelets together

Question 19

what are the three stages of coagulation?

Answer 19

initiation of coagulation by formation of prothrombin activator

activation prothrombin to thrombin

conversion of fibrinogen to fibrin

Question 20

What does vasoactive amines do?

Answer 20

release serotonin, kinins, epinephrine to restrict blood vessel (vasoconstriction)

Question 21

thromboplastin

Answer 21

help in formation of permanent clots

Question 22

When does the plasma coagulation happen?

Answer 22

when there is more severed damages on blood vessels & platelet plug alone can’t stop the blood loss

Question 23

platelet factor 3 (PF3)

Answer 23

products released during platelets plug that involved in plasma coagulation

Question 24

When does the extrinsic pathway of forming prothrombin activator happen?

Answer 24

when there is extract of fluid from tissue into plasma

Question 25

When does the intrinsic pathway of forming prothrombin activator happen?

Answer 25

when there is trauma to the blood itself or atherosclerosis

Question 26

clot retraction

Answer 26

the process of blood clot shrink or contract after 3D-fibrin network formed

Question 27

when does the clot dissolution happen?

Answer 27

when the new fibroblasts arrive at the injury site & repair proces start

Question 28

during retraction, what also happen to the wound/injuries site?

Answer 28

the edges of wounds are pulled together the fluids also ooze out of the clot in form of serum

Question 29

What is the factor III?

Answer 29

thromboplastin

Question 30

What is the factor IV?

Answer 30

calcium

Question 31

platelet actomyosin

Answer 31

the protein that help the clot retraction

Question 32

The steps in forming prothrombin activator of extrinsic pathway?

Answer 32

1) Factor III and tissue phospholipid(TF) are released by damaged cells 2) Factor III + IV act on Factor VII to form complex VIIa 3) Complex VIIa + TF acts on factor X-\> complex Xa 4) Complex Xa form with TF & factor V to form prothrombin activator

Question 33

The steps in forming prothrombin activator in intrinsic pathway?

Answer 33

1) PF3 and Calcium are released 2) Factor XIIa acts on XI -\> complex XIa 3) XIa acts on IX -\> IXa 4) IXa + VIIIa + PF3 + Calcium -\> Xa 5) Xa + PF3 + Va -\> prothrombin activator

Question 34

Where is the prothrombin produced? What vitamin is required for this?

Answer 34

in the liver by endothelial cells vitamin K

Question 35

What is the last step of blood clot (or plasma coagulation)?

Answer 35

conversion of fibrinogen into fibrin

Question 36

What are the two factors in plasma coagulation that are not proteins?

Answer 36

factor IV (calcium) PF3 (tissue phospholipid)

Question 37

Lack of factor VIII will cause what disease? What pathway in forming prothrombin activator is affected?

Answer 37

hemophillia intrinsic pathway

Question 38

Mechanism of forming thrombin from prothrombin?

Answer 38

prothrombin activator and Ca2+ act on prothrombin to produce thrombin

Question 39

The steps in conversion of fibrinogen to fibrin

Answer 39

1) thrombin split fibrinogen molecule into fibrin monomer 2) fibrin monomer unites -\> fibrin polymers 3) Complex XIIIa acts on fibrin polymers to form strong 3D fibrin network surround the platelet plug

Question 40

Is it true that factors, once activated adhere to original site of injury and act spreadly?

Answer 40

No, they all act locally

Question 41

Is it true that extrinsic and intrinsic pathway doesn't have anything in common?

Answer 41

No, they share the similarites in steps fornming fibrin from prothrombin

Question 42

NSAIDs Example of this type of family drug How long does it take for platelets restores it functions if we stop this drug?

Answer 42

reversible cox 2 inhibitor ibuprofen, acetaminophen, naproxene right away

Question 43

What does thrombin do?

Answer 43

activate factor XIII and I activate platelet plug to increase aggregation

Question 44

hemophillia Example of this disease

Answer 44

inherited disease that lack of factor VIII uncontrolled bleeding on "Clean" cut vessel while damaged tissue may clot

Question 45

Mechanism of clot dissolution?

Answer 45

clot produce plasminogen and clot dissolution occur

Question 46

thrombocytopenia Cause of this disease? Consequence of it?

Answer 46

the inadequate number of platelets dietary deficiency of vitamin B12 & folic acid prolong bleeding time & impaired clot retraction

Question 47

Coumadin How long does it take for this drug to work?

Answer 47

the anticoagulant that inhibit the sysnthesis of vitamin K -\> key plasma proteins factors are not produced 36-48 hours

Question 48

what are the mechanisms to prevent coagulation under normal condition?

Answer 48

the repellence btw negative charge of plasma proteins & of endothelial cells the circulation of anti-coagulant agents

Question 49

What are the anti-coagulant agents? Each effect on plasma proteins?

Answer 49

fibrin absorbs most thrombin antithrombin II binds to excess thrombin heparin: interferes with activation of factor X

Question 50

aspirin What does it do?

Answer 50

the irreversible cox-2 inhibitor inhibit the production of platelet & thromboxane A2

Question 51

When should a patient have a surgery if he/she is using aspirin?

Answer 51

in one week after the day stop using aspirin

Question 52

plasminogen

Answer 52

the enzyme that degrade the fibrin clots

Question 53

What is the cause of Von Willibrand's disease? Consequence?

Answer 53

the deficiency of vWF poor platelet adherence to injuries site & low lvl of factor VIII prolong bleeding time

Question 54

What is chelator used for? Why?

Answer 54

in blood being draw for testing because it binds with Ca2+ -\> inhibit the coagluation pathways

Question 55

What test is used to measure the deficiency of platelet number? What does this test also measure?

Answer 55

complete blood count RBC/ WBC/ hematocrit & hemoglobin

Question 56

What blood test is used to evaluate the intrinsic pathway? extrinsic pathway?

Answer 56

partial thromboplastin time (PTT) prothrombin time (PT)

Question 57

What blood test is used to evaluate the vW disease?

Answer 57

platelet aggregation test

Question 58

What blood tests that are used to confirm the heparin contamination? What do these tests measure in common?

Answer 58

prothrombin & thrombine time test partial thromboplastin time test time to clot

Question 59

What drug that inhibit platelet production & thromboxane A2?

Answer 59

aspirin

Question 60

What drug is used in blood being drawn to prevent coagulation?

Answer 60

chelator

Question 61

What drug that will have platelet restored its function right away when it is stoped? Why?

Answer 61

NSAIDs because it is reversible cox 2 inhibitor

Question 62

What drugs that inhibit the vitamin K synthesis so the plasma factors will not be produced?

Answer 62

Coumadin

Question 63

What drug is use to be anti-coagulant to interfere with activation of factor X?

Answer 63

heparin

Question 64

What proteins that adhere platelets to collagen fibers?

Answer 64

von WIllibrand's factor

Question 65

What blood diseases that have inadequate platelets & is caused due to deficiency of vitamin B12 & folic acid?

Answer 65

thrombocytopenia