Sir Almroth Edward Wright contributed to coagulation science by observing the role of which ion?

• A. Calcium
• B. Sodium
• C. Potassium
• D. Magnesium

Answer: (A)

Calcium ions act as essential cofactors in blood coagulation. They enable coagulation factors to bind to phospholipid surfaces on activated platelets and facilitate the assembly of critical enzyme complexes, such as tenase and prothrombinase, which drive the cascade forward to produce thrombin and ultimately form a fibrin clot. This calcium-dependent binding and complex formation explain why clotting requires calcium and why removing it with citrate stops coagulation. Sir Almroth Edward Wright contributed to coagulation science by recognizing the importance of calcium ions in enabling clot formation, highlighting their pivotal role in the coagulation process.