Which substance is NOT typically found in plasma?

Plasma is the liquid component of blood, which carries various substances throughout the body. It consists primarily of water, which makes up about 90% of its volume. Additionally, plasma contains nutrients, hormones, proteins, electrolytes, and waste products.

Red blood cells, however, are not found in plasma itself; they are cellular components that are suspended in the plasma. They are involved in the transport of oxygen and carbon dioxide but are categorized separately from the liquid part of blood. This distinction is important because red blood cells are contained within the blood but are not part of the plasma, which is specifically the non-cellular portion.

Therefore, identifying red blood cells as not typically found in plasma is accurate, as plasma is the liquid matrix that surrounds these cells and other components within the circulatory system.