Final answer:
Human stem cells differentiate into specialized blood cells through a process called hematopoiesis, which is triggered by hemopoietic growth factors. The differentiation potential of stem cells varies depending on their source, with embryonic stem cells being pluripotent and adult stem cells being multipotent. Induced pluripotent stem cells (iPSCs) are a recent innovation that can differentiate into a wide range of cell types.
Step-by-step explanation:
The process that stimulates human stem cells to differentiate into specialized blood cells is known as hematopoiesis. This process begins when hematopoietic stem cells in the bone marrow are exposed to crucial chemical signals known as hemopoietic growth factors. These growth factors trigger the stem cells to divide and begin the differentiation into various blood cell types. There are several sources of stem cells, including human embryonic stem cells (hESCs), which are pluripotent, and adult stem cells, which are multipotent and present in tissues like bone marrow and skin. Additionally, stem cells from umbilical cord blood and deciduous teeth are also multipotent. A groundbreaking advancement has been the development of induced pluripotent stem cells (iPSCs), which are reprogrammed adult cells that can differentiate into cell types from all three germ layers, mimicking embryonic stem cells' capabilities.
The variety of blood cells, including those involved in the immune response, are derived from multipotent hematopoietic stem cells. These cells can differentiate into cell types such as phagocytic cells, which ingest and destroy pathogens, and lymphocytes, which play a role in adaptive immunity. The continuous differentiation of these cells throughout adulthood is essential to replace blood cells regularly lost due to aging or functioning.