Hemostasis

Question 1

What is hemostasis

Answer 1

Process by which the body maintains a delicate balance between bleeding and clotting.

Question 2

What is the Tunica Intima?

Answer 2

Lining separating flowing blood from the vessel, made of endothelial cells.

Question 3

Tunica media: Endothelial cells synthesize and secrete procoagulants, anticoagulants, and fibrinolytics. What are they?

Answer 3

von Willebrand factor (vWF)
Tissue factor
Nitric Oxide
Prostacyclin
Thromboxane A2
ADP
Tissue Factor Pathway Inhibitor

Question 4

T/F: the tunica media

Answer 4

Forms a barrier separating fluid contents within the blood vessel from the highly thrombogenic material that lies in the Tunica Media

Question 5

What are the endothelial cell procoagulants?

Answer 5

Von Willebrand factor & tissue factor

Question 6

What is Von Willebrand factor necessary for?

Answer 6

Necessary cofactor for adherence of platelets to the subendothelial layer

Question 7

What is tissue factor necessary for

Answer 7

Activates the clotting cascade pathway when injury to the vessel occurs

Question 8

What are the endothelial cells: vasoconstriction

Answer 8

Thromboxane A2

Adenosine diphosphate (ADP)

Question 9

What are the endothelial cells: vasodilation

Answer 9

Nitric oxide

Prostacyclin

Question 10

What are the endothelial cells: coagulation inhobitors

Answer 10

Tissue Factor Pathway Inhibitor

Question 11

Where is the tunica media located?

Answer 11

sub endothelial

Question 12

What are the characteristics of the tunica media

Answer 12

Extremely thrombogenic & Very active

Question 13

Parts of the tunica media subendothelial layer

Answer 13

Collagen & Fibronectin

Question 14

What is the tunica adventitia?

Answer 14

Third layer (outermost)

Question 15

What does the tunica adventitia do?

Answer 15

Control of blood flow by influencing the vessel’s degree of contraction.

Question 16

What 2 substances help control the blood flow by influencing the vessel’s degree of contraction.

Answer 16

Nitric oxide & prostacyclin

Question 17

Where are platelets formed?

Answer 17

bone marrow

Question 18

Platelet cell characteristics

Answer 18

Contain mitochondria ~
Glycogen stores ~
Contractile proteins, calcium, enzymes ~
Alpha (α) granules ~
vWF
Fibrinogen
Fibronectin
Platelet factor 4
Platelet growth factor
Dense granules
Serotonin
ADP
ATP
Histamine
Epinephrine

Question 19

Produce ________.
Activate coagulation factors
Influence recruitment of platelets

There is no ____, _____, _____

Inactive unless activated as a result of ________

Adequate hemostasis is not possible in the absence of ________

Answer 19

thrombin

nucleus, RNA, DNA

tissue trauma

activated platelets

Question 20

Produce ________.
Activate coagulation factors
Influence recruitment of platelets

There is no ____, _____, _____

Inactive unless activated as a result of ________

Adequate hemostasis is not possible in the absence of ________

Answer 20

thrombin

nucleus, RNA, DNA

tissue trauma

activated platelets

Question 21

What is the goal in clot formation with platelets

Answer 21

Goal: Adherence of the platelet to the injured vessel wall and the subsequent response of the clotting cascade to form a stable clot and halt the progress of the bleeding.

Question 22

Vessel injury and clot formation

Answer 22

slide 20

Question 23

adhesion - primary plug

Answer 23

slide 21/23/26

Question 24

What factor is responsible for the adhesion of platelets?

Answer 24

vWF

Question 25

What are zymogens?

Answer 25

activation of cofactors

Question 26

Cofactors are enzymes with the exception of factor ____ & ___

Answer 26

V and VIII

Question 27

Coagulation cofactors (zymogens) circulate in an _____ state until they are activated to assist in the process of _______

Answer 27

inactive coagulation

Question 28

What are the 2 clotting pathways?

Answer 28

Extrinsic Pathway Intrinsic Pathway Two separate and distinct pathways Function independent of each other but in conjunction with platelet activity and the common coagulation pathway

Question 29

What is the Extrinsic Pathway / Tissue Factor Pathway

Answer 29

Activated by injury “outside” the vessel wall Organ trauma or crushing injury Factor III - tissue factor Factor VII - proconvertin

Question 30

What is Intrinsic Pathway / Contact Activation Pathway

Answer 30

Initiated when damage occurs to blood vessel itself Initiated by prekallikrein and high molecular weight kininogen Factor XII Factor XI Factor IX Factor VIII

Question 31

What is the common pathway of intrinsic and extrinsic pathways

Answer 31

Formation of XV - Prothrombinase complex Factor X - Stuart-Prowers Factor V - Proaccelerin Activation of Factor II - Prothrombin Factor IIa - Thrombin Activation of Factor I - Fibrinogen Factor Ia - Fibrin Activation of Factor XIII - Fibrin Stabilizing ~~ Stable Clot ~~

Question 32

The common pathway is the _____ pathways of the coagulation cascade

Answer 32

terminal

Question 33

T/F: Fibrin (Factor Ia) together with Fibrin stabilizing factor (Factor XIII) secure the initial clot as a stable secondary plug and bleeding stops.

Answer 33

True

Question 34

Thrombin activates factors

Answer 34

V, VIII, I, XIII

Question 35

Thrombin recruits platelets to

Answer 35

the injured area

Question 36

Adequate _____ must be present to activate sufficient fibrin to form a “stable” or “secondary” clot.

Answer 36

Thrombin

Question 37

``` Thrombin (the anticoagulant) 1. Prevents runaway clot formation Release tPA - which 2. Stimulates protein C and S Inhibits clot formation - which 3. Works with antithrombin III - which ```

Answer 37

1. releases tPA 2. inhibits clot formation 3. Interferes with coagulation

Question 38

which electrolyte is highly involved in many parts of the common pathway

Answer 38

Ca

Question 39

What are sources of coag factors

Answer 39

Most formed by liver Calcium from Diet vWF formed in endothelial cells II, VII, IX, X are vitamin K dependent