Bone marrow Bone marrow Bone marrow is a semi-solid tissue which may be found within the spongy or cancellous portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production or hematopoiesis. It is composed of hematopoietic cells, marrow adipose tissue, and supportive stromal cells. In adult humans, bone marrow is primarily located in the ribs, vertebrae, sternum, and bones of the pelvis. On average, bone marrow constitutes 4% of the total body mass of humans; in an adult having 65 kilograms of mass (143 lb), bone marrow typically accounts for approximately . Human marrow
History of beliefs about the human body History of beliefs about the human body The human body has been subject of much debate. How people are defined, and what defined them – be it their anatomy or their energy or both – depends on culture and time. Culture not only defines how sex is perceived but also how gender is defined. Today gender, sex, and identity continue to be of much debate and change based on what place and people are being examined. The early modern idea of the body was a cultural ideal, an understanding and approach to how the body works and what place that