Review

Question 1

Deficiencies in what clotting factors can cause signficant bleeding?

Answer 1

• Factors 8, 9 (hemophilias)
• vWF

Question 2

Steps in Primary Hemostasis:

Answer 2

1. Endothelium injured and basement membrane exposed.
2. vWF binds to exposed collagen.
3. vWF elongates into an open conformation revealing platelet binding sites.
4. Platelets bind to vWF, become active, and release granules.
5. More platelets recruited and aggregate onto elongated vWF.
6. Platelets change shape and aggregate.
7. Platelet plug forms.

Question 3

Factors of the extrinsic pathway:

Answer 3

• Tissue factor
• Factor 7

Question 4

The initiation complex from the extrinsic pathway is:

Answer 4

TF:F7a:F9a

Question 5

The common pathway:

Answer 5

F10:F5:Prothrombin:Thrombin:Fibrin

Question 6

Catalyst clotting factors are:

Answer 6

5 and 8

• 5 and 10 (faster prothrombin to thrombin)
• 8 and 9 (more F10)

Question 7

Intrinsic pathway factors are:

Answer 7

F12:F11:F9:F13

Question 8

Vitamin K dependent Clotting Factors:

Answer 8

2, 7, 9, 10

Question 9

Functions of vWF:

Answer 9

1. accordion/landing site for platelets
2. extends half-life of F8

Question 10

Thrombomodulin:

Answer 10

• anticoagulant
• sink for thrombin
• thrombin-thrombomodulin activates Protein C

Question 11

Protein C and Protein S:

Answer 11

• Anticoagulants
• Protein S cofactor for Protein A
• APC shuts off catalysts F5 and F8

Question 12

von Willebrand Disease:

Answer 12

• platelets don’t adhere properly
• F8 has very short half-life
• most common inherited bleeding disorder

Question 13

What is the most commonly inherited bleeding disease?

Answer 13

von Willebrand disease

Question 14

What is the most commonly inherited clotting disease?

Answer 14

Factor V Leiden deficiency