What is the primary function of plasma?

The primary function of plasma is indeed its role as the liquid part of blood. Plasma serves as the medium that carries various components of blood, including red blood cells, white blood cells, and platelets, throughout the circulatory system. It is a critical part of the blood's physiology, comprising about 55% of total blood volume. Plasma itself is composed of water, proteins, electrolytes, nutrients, hormones, and waste products, making it essential for numerous bodily functions.

While transporting hormones is a function of plasma, it is not the primary role; rather, it is part of the broader function of allowing substances to circulate in the bloodstream. Similarly, providing immunity involves components like antibodies found within the plasma but is a secondary aspect since the plasma's main identity is as the liquid connective tissue holding these cells and proteins together. Facilitating blood clotting is another important function, as plasma contains clotting factors, but again, this specific role does not define plasma's primary function, which is its capacity as the liquid component that enables the movement of cells and nutrients in the body.