Part 1
A 6 month old baby was brought to his pediatricians office due to an injury that would not stop
bleeding . Briefly, the baby had tried to follow his 3 year old sister up the stairs when he
slipped and fell, hitting his mouth on the linoleum floor of the kitchen. The mother reported a
small wound on the child’s gum, but with copious amounts of blood loss. She applied cold
compresses for 15 minutes, the bleeding eventually stopped, but minutes later, the bleeding
started again.
During a thorough checkup of the baby, the pediatrician noticed bruises on the legs and arms.
Upon examination of the injured gum area, bleeding started again.
The pediatrician asked the mother if there was a history of bleeding disorders on the maternal
side of her family. The mother was not sure, although she thought she may have had a great
uncle who died when he was young of a blood disorder.
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1, What 3 physiological processes are activated to reduce or stop bleeding?

2. What steps are required to form a platelet plug?

3. What 3 pathways are involved in coagulation?

4. What activates the extrinsic pathway?

5. What activates the intrinsic pathway?
6, What are the steps of the common pathway?

7. What is the end result of the clotting cascade?
The child is found to have a lack of von Willebrand factor.
What is the purpose of Von Willebrand factor?
How would this be expected to affect platelet plug formation?
How would this be expected to affect clotting?
Name 3 ways that an anticoagulant could act to interfere with the clotting mechanisms ( it does
not have to be a real drug mechanism, but just a rational approach)
Part 2
Determine whether each of the following will increase/stabilize clot formation, decrease clot formation
or dissolve clots that have formed
Activation of antithrombin III
Activation of plasminogen
Inhibition of factor X
Inhibition of platelet activation
Inhibition of thrombin
Activation of fibrinogen