What percentage of whole blood is composed of plasma?

Plasma constitutes approximately 55% of whole blood. This yellowish fluid is crucial as it carries various components, including water, electrolytes, proteins, hormones, and waste products. Being the liquid portion of blood, plasma plays a vital role in transportation, maintaining blood pressure and volume, and providing essential nutrients to cells throughout the body. Understanding this composition is important, especially in fields like emergency and tactical medicine, as it helps in fluid resuscitation strategies and managing traumatic blood loss in critical situations. Knowing that plasma makes up the majority of the volume in whole blood aids in grasping the overall structure and function of the circulatory system.