Coagulation

Question 1

What is physiological hemostasis

Answer 1

Repair of everyday wear and tear, happening all the time

Question 2

What is pathological hemostasis

Answer 2

-Clotting in the absence of hemorrhage
-Excessive clotting
-Clotting in the wrong location

Question 3

What are the basic components that maintain hemostasis

Answer 3

Vessels
Platelets
Coagulation factors
Inhibitors

Question 4

What are the steps of hemostasis

Answer 4

Vasoconstriction
Platelet Activation
Coagulation cascade
Antithrombotic control

Question 5

Vasoconstriction -

Answer 5

VERY fast, neurogenic
Vessel spasm

Question 6

What are platelets filled with

Answer 6

Alpha and dense granules

Question 7

What is in alpha granules

Answer 7

Adhesion molecules and GFs

Question 8

What is in dense granules

Answer 8

Activators, cofactors, some GFs

Question 9

What important things live under the endothelial layer of the vessel

Answer 9

von Willebrand factor
collagen

Question 10

Who produces vWF

Answer 10

Endothelial cells, platelets, megakaryocytes

Question 11

Where is vWF stored

Answer 11

Weibel palade bodies

Question 12

What does vWF bind to

Answer 12

Glycoprotein IIb/IIIa on the platelet

Question 13

What are the steps involved in making the platelet plug

Answer 13

Adhesion
Shape change
Secretion
Aggregation

Question 14

What happens during adhesion

Answer 14

Platelets bump into exposed vWF –> weak attachments
Roll along vessel wall and encounter collagen –>
Integrin forms stronger attachments

Question 15

What happens during shape change

Answer 15

Collagen and thrombin (and platelet-activating factor and ADP) activate platelets
Platelets change shape
More stable plug is formed

Question 16

What happens during secretion

Answer 16

Platelets dump all their granules
Platelet plug activates other platelets as they pass

Question 17

What happens during aggregation

Answer 17

Platelets flip phosphatidyl serine to the outside of their membrane (now negatively charged)
Fibrinogen bridges form between platelets

Question 18

Why is it important for the platelets membranes to have a negative charge

Answer 18

Helps with the coagulation cascade

Question 19

What is the goal of secondary hemostasis

Answer 19

To have fibrin (glue) form around the platelet plug to create a good seal

Question 20

Which coag factors are made in the liver

Answer 20

II, VII, IX, X, XII, XIII

Question 21

Which coag factors need to be carboxylated

Answer 21

II, VII, IX, X

Question 22

What are the three pathways in the coag cascade

Answer 22

Intrinsic
Extrinsic
Common

Question 23

What molecules are involved in the extrinsic pathway

Answer 23

Tissue factor (III), VII

Question 24

What sets off the extrinsic pathway

Answer 24

Trauma that exposes TF to blood

Question 25

What molecules are involved in the common pathway

Answer 25

X, V, II (thrombin)

Question 26

What molecules are involved in the intrinsic pathway

Answer 26

XII, XI, IX, VIII

Question 27

What sets off the intrinsic pathway?

Answer 27

Damage to endothelial cell

Question 28

What activates the common pathway

Answer 28

TF + VII and/or VIII

Question 29

Which pathway is the main activator of the cascade

Answer 29

Extrinsic

Question 30

Draw the coagulation cascade

Answer 30

Question 31

What test is used to test the intrinsic pathway

Answer 31

aPTT Activated partial thromboplastin time

Question 32

What test is used to test the extrinsic pathway

Answer 32

PT Partial thromboplastin

Question 33

What test is used to test the common pathway

Answer 33

aPTT and PT - remember the cascade is like a Y

Question 34

What factors are hemophiliacs lacking

Answer 34

IX and/or VIII

Question 35

What factors will be impacted by a vit K deficiency

Answer 35

II, VII, IX, X

Question 36

Why do we care about vitamin K

Answer 36

Coag factors need to be modified in order to be active, the enzyme that drives the redox cycle needs vit K in order to work

Question 37

What does thrombin do

Answer 37

Cleaves fibrinogen --> fibrin Activates platelets Mediates vascular permeability Activates a fibrinolysis inhibitor

Question 38

What is the ultimate goal of hemostasis

Answer 38

To return normal blood flow following an injury

Question 39

Do animals that have hypocalcemia have a hard time clotting

Answer 39

NO. Coag needs very little Ca. To not have enough Ca to not clot you would already be dead

Question 40

Do animals lacking factors XI and XII clinically bleed

Answer 40

No