The tubular shaft of a long bone is the:

1. It runs between the two ends. 2. Its walls are compact bone. 3. The diaphysis is the tubular shaft that runs between the proximal and distal ends. 4. So the answer is the diaphysis. _Source: OpenStax 'Anatomy and Physiology 2e', Ch 6 'Bone Tissue and the Skeletal System'_