SEM of Human bone. This image shows the cancellous (spongy) bone of the human shin. Bone tissue is either compact or cancellous. Compact bone usually makes up the exterior of the bone, while cancellous bone is found in the interior. Cancellous bone is characterised by a honeycomb arrangement of trabeculae. These structures help to provide support and strength. The spaces within this tissue normally contain bone marrow, a blood forming substance.  Magnification is x40 when printed 10 cm wide.