Final answer:
Bone marrow samples in children are typically taken from the pelvic bones near the iliac crest. This method is chosen because of its accessibility and safety. Red bone marrow, involved in blood cell production, is located in this area.
Step-by-step explanation:
In children, bone marrow samples are usually taken from the region near the iliac crest of the pelvic bones. This area is chosen for the procedure because it is more accessible due to its proximity to the body surface, and it is relatively isolated from most vital organs, making it safer for sampling. The process involves inserting a large-bore needle into this region to extract bone marrow. Red bone marrow is found in the head of the femur and flat bones such as the ilium, where it actively produces new blood cells.
Although direct sampling of bone marrow has been the traditional method, now stem cells can sometimes be isolated from a blood sample and then grown in culture with hemopoietic growth factors. This technique can avoid the pain and complexity of direct sampling from the bone marrow.