Hemostasis

Question 1

Hemostasis

Answer 1

Stopping blood loss in response to vascular injury

Question 2

Steps of hemostasis

Answer 2

1. vascular constriction
2. formation of platelet plug
3. formation of the blood clot
4. Fibrous organization

Question 3

Vascular constriction

Answer 3

Reduces blood flow to site of injury

Question 4

Formation of platelet plug

Answer 4

Adhesion and aggregation of platelets at the site of injury

Question 5

What two factors aid in formation of platelet plug

Answer 5

vWF and fibrinogen

Question 6

Formation of a blood clot

Answer 6

Fibrinogen is converted to fibrin which then adheres more firmly to the platelets (sticky). Blood is also transformed into a gel

Question 7

Fibrous organization

Answer 7

Fibrin mesh is produced all around the platelet plug and holds this in place, eventually goes into fibrinolysis (which breaks down the clot and allows for normal blood flow to resume)

Question 8

Petechiae

Answer 8

Small red or purple spot caused by bleeding into the skin

Question 9

Purpura

Answer 9

A rash of purple spots on the skin caused by internal bleeding from small blood vessels

Question 10

Vasculitis

Answer 10

Inflammation of blood vessels (thickening, wearing down, narrowing, scarring)

Question 11

hematoma

Answer 11

Solid swelling or mass of clotted blood within the tissue

Question 12

Ecchymosis

Answer 12

Discoloration of the skin due to bleeding underneath (usually internal structural bleeding)

Question 13

Thrombosis

Answer 13

Local coagulation or clot in circulatory system

Question 14

Embolism/thromboembolism

Answer 14

The obstruction of a blood vessel due to a blood clot or foreign substance that lodges itself in vessel. Migrates from some place else (PE)

Question 15

Infarction

Answer 15

Tissue death (necrosis) due to lack of O2

Question 16

What is the big cell that makes platelets

Answer 16

megakaryocytes

Question 17

What is the life span of a platelet

Answer 17

7-10 days

Question 18

What factor do platelets contain

Answer 18

vWF

Question 19

What is the role of vWF

Answer 19

acts as the glue in platelet plug

Question 20

What is the initial step of the platelet in clotting

Answer 20

Adherence to collagen on the surface of injured vessel

Question 21

What does collagen do at site of injury

Answer 21

It triggers the activation of the platelets which causes them to adhere and aggregate to each other

Question 22

Which factor converts prothrombin to thrombin

Answer 22

Factor X(a)

Question 23

Where does conversion of prothrombin to thrombin occur during the pathways

Answer 23

It occurs where intrinsic and extrinsic join

Question 24

What catalyzes the conversion of fibrinogen to fibrin

Answer 24

Thrombin. It stabilizes and solidifies the aggregates

Question 25

Primary hemostasis

Answer 25

Platelet plug formation

Question 26

Secondary hemostasis

Answer 26

Coagulation of fibrin

Question 27

Fibrinolytic system

Answer 27

Breaks the fibrinogen clot in order for blood flow to be reestablished once vessel is healed

Question 28

What is vitamin K involved in forming

Answer 28

1. Prothrombin 2. Factors VII, IX, and X 3. Protein C

Question 29

Where do you get vitamin K from

Answer 29

1. Normal diet | 2. Bacteria in the gut

Question 30

Which blood test measures intrinsic pathway factors

Answer 30

PTT

Question 31

Which blood test measures extrinsic pathway factors

Answer 31

PT

Question 32

What affect will a vitamin K deficiency have

Answer 32

Will cause an increase in PT and PTT because it changes the way the pathways function (basically an increase in bleeding, clotting cascade not working properly)

Question 33

Hemophilia

Answer 33

Severe bleeding disorders

Question 34

Hemophilia A

Answer 34

Factor VIII deficiency

Question 35

Hemophilia B

Answer 35

Factor IX deficiency

Question 36

vWF role in disorders

Answer 36

most common cause of bleeding disorders (when absent), aids w/platelet adhesion

Question 37

DVT

Answer 37

Thrombus occurs in lower extremity vein, can detach and travel to lungs (PE)

Question 38

Thrombocytopenia

Answer 38

Abnormally low platelet count in blood stream. Usually anything below 50,000. Pt will not clot properly. Very asymptomatic but may have frequent nosebleeds or petechia

Question 39

Pulmonary embolism

Answer 39

An embolus, meaning it is a clot that has migrated to the lungs from other parts of the body. Usually comes from the lower legs

Question 40

Disseminated intravascular coagulation (2 step process)

Answer 40

1. Starts when there is over activation of clotting cascade, results in blood clots in small blood vessels (organ damage) 2. As the coagulation cascade consumes these clotting factors, normal clotting is disrupted elsewhere and severe bleeding can occur

Question 41

Bleeding time

Answer 41

Measures platelet function. Make a small incision on pt forearm (2-9mins)

Question 42

Platelet count

Answer 42

Only test that determines platelet number and concentration (150,000-450,000)

Question 43

partial thromboplastin time (PTT)

Answer 43

Measurement of the intrinsic pathway. Assess the patients response to heparin.

Question 44

Prothrombin time (PT)

Answer 44

Measurement of the extrinsic pathway. Assess the patients response to coumadin/calcium

Question 45

D-dimer

Answer 45

Test for DVT/PE but better to rule out than rule in. Tests the fibrin degradation product in the blood (this occurs after the breakdown of clot)

Question 46

Platelet function test

Answer 46

Measures the ability of the platelets to aggregate. Helps identify bleeding disorders

Question 47

What mechanisms prevent excess thrombosis

Answer 47

1. TFPI - inhibits extrinsic pathway 2. Antithrombin 3 - inhibits VII, IX, XI and thrombin 3. Activated protein C (w/protein S) - inhibits X and thrombin 4. Plasmin - fibrinolysis

Question 48

Adhesion

Answer 48

1st step in blood clot formation, platelets stick to endothelium

Question 49

Aggregation

Answer 49

2nd step in blood clot formation. Platelets clump together due to fibrin

Question 50

Spreading

Answer 50

3rd step in blood clot formation, platelets change shape, becomes more gel like

Question 51

What factors contribute to developing pathologic thromboses

Answer 51

1. Congenital 2. Acquired -cancer, anemia, IBS 3. Fibrinolytic abnormalities 4. Situational - prolonged immobilization, pregnancy, surgery, birth control

Question 52

What are two compounds that are involved in fibrinolysis

Answer 52

urokinase, tPA