After applying a tourniquet, the injury from a patient's leg stops bleeding. This is called:

• A. Hematemesis.
• B. Hemolysis.
• C. Hemiplegia.
• D. Hemostasis.

Answer: (D)

Stopping bleeding is called hemostasis. When a tourniquet is applied, it helps halt the flow of blood from the injured leg, giving the body's own hemostatic processes time to seal the wound. Hemostasis begins with the blood vessels constricting to reduce flow, then platelets gather to form a plug, and coagulation factors create a fibrin clot that stabilizes the plug. This coordinated action stops the hemorrhage and maintains blood in the circulatory system. The other terms refer to different conditions: hematemesis is vomiting blood, hemolysis is the destruction of red blood cells, and hemiplegia is paralysis on one side of the body.