17. The Blood

Platelets are similar to erythrocytes in that both structures do not contain a _________________. Platelets are similar to leukocytes in that both their primary functions involve ________________ the body.

Which physiological response causes a reduction in blood flow immediately after a blood vessel injury?

Which of the following statements about vascular spasms is false?

Prostacyclin is a hormone that is normally active in the blood but becomes inactive when a blood vessel ruptures and hemostasis begins. Considering this, which of the following is the most likely function of prostacyclin?

Which of the following is the most likely outcome if platelets could not release aggregating agents?

Which option correctly arranges/orders the components of the coagulation pathway?

What would happen if plasminogen was activated before clot retraction?

Number the steps of hemostasis in order, putting 1 by the first event, 2 by the second, and so on.      

____The intrinsic/contact activation and extrinsic/tissue factor pathways produce factor Xa.      

____The clot retracts.      

____Thrombin converts fibrinogen to fibrin, and fibrin glues the plug together.      

____Platelets are activated, and the platelet plug forms.      

____Vasoconstriction and increased tissue pressure decrease blood flow through the vessel.      

____Tissue plasminogen activator activates plasmin, which degrades fibrin.      

____The common pathway produces thrombin.

​​How do the intrinsic/contact activation and extrinsic/tissue factor coagulation pathways differ? How are they similar?

What are the overall goals of the common pathway of coagulation?

Which of the following is not an anticlotting agent produced by endothelial cells?

a. Prostacyclin

b. Protein C

c. Antithrombin-III

d. Warfarin

Tissue plasminogen activator, urokinase, and plasmin are important components of:

a. coagulation.

b. fibrinolysis.

c. platelet plug formation.

d. hemostasis.

The anticoagulant drug warfarin primarily disrupts the extrinsic/tissue factor coagulation pathway. Explain why disrupting only this pathway disrupts the entire coagulation cascade.

Cirrhosis of the liver often reduces production of many types of plasma proteins, including albumin and clotting factors. Predict the effects on the body of decreased numbers of these proteins in the plasma. Would this also affect the number of γ-globulins in the plasma? Why or why not?

Elise​​ is a 36-year-old woman who has volunteered to donate red bone marrow to a patient in need of a bone marrow transplant for aplastic anemia. The physician performing the bone marrow extraction is an intern, and it is her first time doing the procedure. She asks that you prepare a site on Elise's tibia for the procedure. Is this a good place for red bone marrow to be extracted, considering Elise's age? Why or why not? Can you suggest an alternative location? Explain.