Answer to Question #301991 in Human Anatomy and Physiology for rawan

Question

These two questions about anesthetizing a rabbit

1.How does the coagulation time of the test tube with heparin change? Why?

2. How does the coagulation time of the test tube with Lung tissue immersion liquid change

Answer 1

1. If an appropriate concentration of heparin is added to whole blood the clotting time is prolonged, due presumably to the inactivation of C.F. by heparin: “available” heparin disappears during clotting and none is found in the serum.The AT-heparin complex, by neutralizing thrombin, suppresses thrombin-mediated amplification of the coagulation cascade and inhibits thrombin-mediated conversion of fibrinogen to fibrin.

The reason for this change in clotting times can be as a result of function of the coagulation factors involved. The two most commonly used measures of clotting times are prothrombin time (PT) and activated partial thromboplastin time (aPTT).

2. The coagulation time is an excellent screening test for the vascular platelet phase of hemostasis. It depends on an intact vasospastic response in a small vessel and an adequate number of functionally active platelets.