MICROANATOMY

Detailed explanation-1: -Thrombin converts fibrinogen, a blood clotting factor that is normally dissolved in blood, into long strands of fibrin that radiate from the clumped platelets and form a net that entraps more platelets and blood cells.

Detailed explanation-2: -The proteins collagen and thrombin act at the site of the injury to induce platelets to stick together. As platelets accumulate at the site, they form a mesh that plugs the injury.

Detailed explanation-3: -One important clotting factor is fibrin, a long, thin, and sticky protein. When it is turned on, it forms a mesh to hold the platelet plug in place. This is called a fibrin clot. The mesh also traps red blood cells to form a blood clot.

Detailed explanation-4: -Fibrin forms long strands of tough insoluble protein that are bound to the platelets. Factor XIII completes the cross-linking of fibrin so that it hardens and contracts. The cross-linked fibrin forms a mesh atop the platelet plug that completes the clot.

Detailed explanation-5: -During clotting in vivo, fibrin is being formed by thrombin on or near the platelet surface at the same time as platelets aggregate, 7 and in images of clots, fibrin connects platelet aggregates. Thus, fibrin is important for platelet functions as well as for gelation.