Blood is fluid connective tissue that consists of two main components, plasma and formed element. Blood plasma is a clear extracellular fluid, which is a mixture of proteins, enzymes, nutrients, wastes, hormones and gases. Formed elements are made up of the blood cells (red blood cells and white blood cells) and platelets. All formed elements are cells except for the platelets, which are tiny fragments of bone marrow cells.
The formed elements can be separated from plasma by centrifuge. On separation of blood components, it is evident that formed elements make up 45% of total blood volume while the plasma makes up 55% of the total volume.
