Humerus fracture Humerus fracture A humerus fracture is a break of the humerus bone in the upper arm. Symptoms are pain, swelling, and discoloration of the skin at the site of the fracture. Bruising appears a few days after the fracture. The neurovascular bundle of the arm may be affected in severe cases, which will cause loss of nerve function and diminished blood supply beneath the fracture. Proximal and distal fractures will often cause a loss of shoulder or elbow function. Displaced shaft and distal fractures may cause deformity, and such shaft fractures will often shorten the length of the upper arm.
Bone marrow in the central skeleton, such as the pelvis, sternum, cranium, ribs, vertebrae and scapulae, and variably found in the proximal epiphyseal ends of long bones such as the femur and humerus. In circumstances of chronic hypoxia, the body can convert yellow marrow back to red marrow to increase blood cell production. At the cellular level, the main functional component of bone marrow includes the progenitor cells which are destined to mature into blood and lymphoid cells. Marrow contains hematopoietic stem cells which give rise to the three classes of blood cells that are found in circulation: white blood cells (leukocytes),