There exists three types of formed elements in plasma: red blood cells, white blood cells and platelets.
The red blood cells carry the oxygen and they are the most numerous. The white blood cells are the defenders of body and they are less abundant. The class of white blood cells is divided in five sub-classes, each with its function.
Platelets help the clotting process and they are membranous cells that contain enzymes.
The process of formation of formed elements is called hematopoiesis.