The role of plasma in the circulatory system is vital for transporting nutrients, hormones, and waste products throughout the body. Plasma, the liquid component of blood, makes up about 55% of its volume. It consists primarily of water, electrolytes, proteins, and other substances. By maintaining a stable pH and osmotic pressure, plasma supports overall homeostasis. Additionally, it plays a role in carrying antibodies and facilitating blood clotting, which are essential for the body's immune response and injury repair.