PHYSIOLOGY
BLOOD PHYSIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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In the blood they are present in greater number than red cells.
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They secrete the main clotting factors.
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They aggregate in the presence of prostacyclin.
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They will adhere to the walls of damaged blood vessels.
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Detailed explanation-1: -If one of your blood vessels gets damaged, it sends out signals to the platelets. The platelets then rush to the site of damage and form a plug (clot) to fix the damage. The process of spreading across the surface of a damaged blood vessel to stop bleeding is called adhesion.
Detailed explanation-2: -Platelets floating by in the blood are attracted to collagen. They quickly move to the site of the injury. In order for the platelets to stick to the collagen, they need a “glue.” The “glue” that sticks platelets to the collagen is a protein in the blood called von Willebrand factor (VWF).
Detailed explanation-3: -Back at the injury site, the vessel walls become sticky and capture the platelets as they float past. A platelet plug forms. The platelets change shape and become stickier. This allows them to attach to the vessel wall and clump together into a plug.