Overview of Normal Hematopoiesis

Abstract

The formed elements of blood include various types of cells or cell fragments, each with different morphology and function. These elements are produced via a process known as hematopoiesis, during which hematopoietic stem cells (HSCs) proliferate and undergo self-renewal or differentiation into lineage-committed progenitors, which continue to differentiate into mature blood cells. This ability to self-renew and the ability to differentiate are two key characteristics of HSCs necessary for normal hematopoiesis. Self renewal is the process by which stem cells enter the cell cycle to divide and give rise to more stem cells, thus preserving the stem cell pool. On the other hand, differentiation allows HSCs to develop into more mature cells with progressive lineage commitment. In general, the ability to self-renew diminishes as maturation and lineage commitment progresses.