What does the bone marrow look like?

Bone marrow is found in the cancellous space of bone and the bone marrow space of long bone and is composed of many types of cells and reticular connective tissue.

It can be divided into red bone marrow and yellow bone marrow according to its structure.

Bone marrow is a spongy tissue that exists in the bone marrow cavity of long bones (such as humerus and femur), flat bones (such as iliac crest and ribs) and irregular bones (sternum, backbone, etc.). The bone marrow that can produce blood cells is slightly red, called red bone marrow.

In some of the marrow cavities in adults, the bone marrow contains many fat cells, is yellow in color, and cannot produce blood cells, called yellow bone marrow. At birth, the bone marrow cavity of the body is full of red bone marrow. With the increase of age, the fat cells in the bone marrow increase, and a considerable part of red bone marrow is replaced by yellow bone marrow. Finally, almost only flat bone cancellous bone has red bone marrow.

This change may be due to the fact that adults do not need all myeloid hematopoietic cells, but some myeloid hematopoietic cells are sufficient to replenish the required blood cells. When the body is severely ischemia, part of the yellow bone marrow can be transformed into red bone marrow, and the ability of hematopoietic recovery.