CanFitPro Personal Training Specialist Practice Test

Where does blood cell formation occur within the skeletal system?

1. In the yellow bone marrow of the long bones

2. In the red bone marrow of the long bones

3. Throughout the entire skeletal system

4. Only in the flat bones

The correct answer is: In the red bone marrow of the long bones

Blood cell formation, also known as hematopoiesis, primarily occurs in the red bone marrow of the long bones. This is where stem cells differentiate into various types of blood cells, including red and white blood cells and platelets. While some bone marrow is found in flat bones, such as the sternum and skull, it is predominantly the red bone marrow within the long bones that is responsible for blood cell formation. The yellow bone marrow found in the long bones is primarily composed of fat cells and has a limited role in producing blood cells. Additionally, although bones in the skeletal system do contain blood vessels and support the transport of nutrients, the primary function of the skeletal system is not blood cell formation. Therefore, choices A, C, and D are incorrect.