17. The Blood

The following is a list of the phases involved in the process of hemostasis:

1. Coagulation
2. Fibrinolysis
3. Vascular spasm
4. Retraction
5. Platelet phase

The correct sequence of these phases is:

(a) 5, 1, 4, 2, 3

(b) 3, 5, 1, 4, 2

(c) 2, 3, 5, 1, 4

(d) 3, 5, 4, 1, 2

(e) 4, 3, 5, 2, 1

Which of the following does not promote multiple steps in the clotting pathway?

a. Platelet phospholipids

b. Factor XI

c. Thrombin

d. Ca²⁺

More than one choice may apply.

A condition resulting from thrombocytopenia is

a. Thrombus formation

b. Embolus formation

c. Petechiae

d. Hemophilia

___ and ____ affect almost every aspect of the clotting process.

(a) Calcium, vitamin K

(b) Calcium, vitamin B12

(c) Sodium, vitamin K

(d) Sodium, vitamin B12

More than one choice may apply.

Place the letters of these events in the order they occur during hemostasis.

What is the difference between prothrombin and thrombin?

Define fibrinolysis

What is the importance of this process?

What contribution from the intrinsic and the extrinsic pathways is necessary for the common pathway to begin?

How is clot overgrowth usually prevented?

List two conditions that may lead to unnecessary (and undesirable) clot formation.

Define hemostasis

List the three major phases of coagulation. Explain what initiates each phase and what the phase accomplishes

In what general way do the intrinsic and extrinsic mechanisms of clotting differ?

Which ion is essential to virtually all stages of coagulation?

Why is aspirin sometimes prescribed for the prevention of vascular problems?