Dehydration and Hemostasis Quiz

Dehydration:

• Deficiency of water in the body
• Causes include diarrhea, vomiting, renal failure, diabetes, heat-stroke, and water deprivation
• Results in a decrease in total body water
• Pathological findings include "tenting" skin, sunken eyes, dry and sticky mucous membranes and subcutaneous tissues

Hemostasis:

• Maintains blood in a clot-free state in normal vessels and induces rapid, localized hemostatic plug at site of vascular injury
• Regulated by vascular wall, platelets, and coagulation cascade
• Platelets adhere to exposed thrombogenic subendothelial matrix and undergo shape changes and release secretory granules to form hemostatic plug
• Tissue factor is exposed at sites of endothelial injury, activates coagulation cascade, and converts circulating fibrinogen to insoluble fibrin
• Permanent plug formed by polymerized fibrin and platelet aggregates
• Thrombin limits hemostasis by binding to protease activated receptors
• Calcium ions required for activation of Factors X, II, XIII, V
• Roles of thrombin include activation of Factor XIII, cleavage of fibrinogen, inducing platelet aggregation and secretion, activating endothelium, and activating monocytes.