Final answer:
The primary location for blood cell production in the human body is the bone marrow, specifically the red marrow, through the process of hematopoiesis.
Step-by-step explanation:
Among the 11 organ systems of the human body, the bone marrow houses the primary location for blood cell production, a process known as hematopoiesis. Initially, in the embryo, blood cells are produced in the yolk sac, but as development progresses, the spleen, lymph nodes, and liver briefly take over these functions. However, later in development, and continuing after birth, red bone marrow becomes the primary site of hematopoiesis.
The red marrow, found inside bones such as the pelvis, ribs, and vertebrae, is responsible for synthesizing red blood cells, white blood cells, and platelets. Children have a more extensive distribution of hematopoietically active marrow in the medullary cavity of long bones, while in adults, it is largely limited to flat bones and the ends of long bones.