👉 The mean fluid, also known as plasma, is a vital component of blood and is essentially the liquid portion that makes up about 55% of its total volume. It's a complex mixture primarily composed of water (about 90%), but also contains proteins, nutrients, hormones, waste products, and cells. This fluid serves as a transport medium for these substances, allowing them to move throughout the body efficiently. It carries oxygen and nutrients to cells, removes waste products, and plays a crucial role in immune responses and maintaining overall homeostasis.