Small holes in the surface of a bone's structure are most likely to be Volkmann canals, according to Augusta Technical College. Volkmann canals carry blood vessels and nerve structures from the surface to the inside of the bone.
Volkmann canals run through the surface of the bone diagonally and connect at right angles to the long Haversian canals inside the bone, says Augusta Technical College. These two types of canals form the bone's vital nutrient and nerve signal delivery system, which is also called the osteon or Haversian system. Osteons are present within the structure of compact bone but not inside spongy bone.