Final answer:
The correct order of the steps of hemostasis is: vascular spasms, platelets binding to exposed collagen fibers, prothrombin conversion to thrombin, fibrinogen conversion to fibrin, prothrombinase formation and activation, fibrin network formation, and trapping of thrombocytes and erythrocytes within the clot.
Step-by-step explanation:
The correct order of the steps of hemostasis, starting with the first event that occurs after a blood vessel is damaged, is as follows:
- B) Vascular spasms & vasoconstriction within damaged blood vessel: When a blood vessel is damaged, the smooth muscle in the walls of the vessel constricts dramatically, reducing blood flow to the area.
- A) Platelets binding to exposed collagen fibers in the wall of the blood vessel to form a plug within the damaged blood vessel: Platelets clump together, become spiked and sticky, and bind to the exposed collagen and endothelial lining of the vessel, forming a plug.
- E) Prothrombin conversion to thrombin: Activated platelets release substances that start a sequence of reactions, leading to the conversion of prothrombin to thrombin.
- F) Fibrinogen conversion to fibrin: Thrombin converts soluble fibrinogen into insoluble fibrin strands, which form a mesh around the platelet plug.
- G) Prothrombinase formation & activation: Prothrombinase, a complex of enzymes, forms and activates thrombin.
- D) Fibrin network formation: The fibrin strands crisscross to form a mesh that strengthens the platelet plug.
- C) Trapping of thrombocytes & erythrocytes within clot along with tightening of clot: The clot tightens, trapping platelets and red blood cells to further stabilize the damaged vessel.