Which type of elements include red blood cells, white blood cells and platelets?

Red blood cells, white blood cells, and platelets are collectively referred to as formed elements. This terminology highlights their status as the solid components of blood that are produced in the bone marrow and play specific roles in the circulatory system.

Formed elements include not only the various types of blood cells but also cell fragments involved in clotting, which are the platelets. These components are essential for oxygen transport, immune response, and hemostasis.

In contrast, fluid elements refer to the liquid portion of blood, primarily plasma, which contains water, electrolytes, hormones, and proteins but does not include the cellular components. Cellular elements is another term that could be misleading, as it can also apply to other cell types, not specifically the components of blood. Soluble elements typically describe substances that dissolve in the plasma, rather than the distinct cellular forms that make up the formed elements. Thus, 'formed elements' is the most accurate categorization for red blood cells, white blood cells, and platelets.