Multiple Choice
The final step in clot formation is __________.
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17. The Blood
Platelets: Hemostasis
Problem 7
Textbook Question
The following is a list of the phases involved in the process of hemostasis:
- Coagulation
- Fibrinolysis
- Vascular spasm
- Retraction
- 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
Verified step by step guidance1
Step 1: Understand the process of hemostasis, which is the body's mechanism to stop bleeding and involves several phases occurring in a specific order.
Step 2: Identify the initial phase, which is the vascular spasm (vasoconstriction) that reduces blood flow immediately after vessel injury.
Step 3: Recognize that the platelet phase follows, where platelets adhere to the damaged vessel wall and aggregate to form a temporary plug.
Step 4: Next is the coagulation phase, where a complex cascade leads to the formation of fibrin strands that stabilize the platelet plug, creating a more permanent clot.
Step 5: After clot formation, retraction occurs, which tightens the clot and brings the edges of the damaged vessel closer together, followed by fibrinolysis, the process that breaks down the clot once healing is complete.
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Phases of Hemostasis
Hemostasis is the body's process to stop bleeding and involves several sequential phases: vascular spasm, platelet phase, coagulation, retraction, and fibrinolysis. Each phase plays a specific role, from immediate vessel constriction to clot formation and eventual clot removal.
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Overview of Hemostasis
Vascular Spasm and Platelet Phase
Vascular spasm is the initial response where blood vessels constrict to reduce blood flow. This is followed by the platelet phase, where platelets adhere to the injury site, forming a temporary plug to prevent further bleeding.
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3:18Vascular Spasm
Coagulation, Retraction, and Fibrinolysis
Coagulation stabilizes the platelet plug by forming a fibrin mesh, creating a stable clot. Retraction then tightens the clot to bring wound edges closer. Finally, fibrinolysis dissolves the clot once healing is complete, restoring normal blood flow.
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7:16Clot Retraction & Fibrinolysis
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