Chapter 7: Blood Platelets and Blood Plasma

forming a platelet plus at the site of an injury

Platelets help control bleeding by:

vasoconstriction

What does the release of serotonin from blood platelets trigger?

platelet-derived growth factor

Promotes the repair of damaged blood vessel walls

fibrinogen

Which plasma protein is necessary for blood clotting?

platelet plug formation

What event is triggered by platelet activation upon contacting exposed collagen fibers? 

coagulation

What event is triggered by fibrinogen being converted into fibrin?

blood clot; coagulation

A network of fibrin threads that entangles platelets is called ______ and is a direct product of _______.

extrinsic

Tissue thromboplastin is initiated by the ______ mechanism.

intrinsic 

Hageman factor is initiated by the ______ mechanism. 

smooth lining of blood vessel

prevents platelet adhesion

antithrombin in plasma

inactivates thrombin and other clotting factors

heparin from basophils

enhances antithrombin

extrinsic mechanism

Which pathway is triggered by damage to vessels/tissue?

intrinsic mechanism

Which pathway is triggered by blood contacting connective tissue?

positive

Blood coagulation is a _______ feedback mechanism.

fibrinogen converted into fibrin

What forms the actual blood clot?

hemostasis

The process that stops bleeding when a blood vessel is injured

collagen

To form a platelet plug, platelets stick to exposed ______ in the vessel wall.

fragments; megakaryoblasts

Platelets are ________ of cells, derived from the shattering of _________.

calcium (Ca2+)

essential for activation of several clotting factors

plasmin 

breaks down fibrin 

blood clot

A network of threadlike fibrin fibers, trapped blood cells, platelets and fluid