Final answer:
Sodium, calcium, and bicarbonate in plasma are important for maintaining acid-base balance and osmotic control of water metabolism.
Step-by-step explanation:
In blood plasma, sodium, calcium, and bicarbonate are described in terms of their roles in maintaining acid-base balance and osmotic control of water metabolism. These substances, typically added to blood collection tubes, impede the blood coagulation process by chelating (binding) calcium ions or inhibiting coagulation factors, which are essential for clot formation. Sodium and bicarbonate are key components of the body's buffering systems, helping to maintain blood pH within a normal range. Calcium is important for muscle contraction and cell permeability.