What role does calcium play in cell excitability?

Excitability of neuronal and cardiac tissue is inversely proportional to extracellular calcium levels Due to the direct effect calcium plays in binding to voltage-gated sodium and potassium channels and slowing their opening Results in altered membrane threshold...

Why is calcium required for clotting?

Ionized calcium is essential for many stages of both coagulation and platelet plug formation Multiple roles in coagulation pathway (Calcium is known as Factor IV): Required for the activation of factors VII, IX and X Acts as a co-factor in the conversion of...