MH 043 Cancellous and Compact Bone

Compact and Spongy Bone

Bone must be decalcified (by exposure to strong acids) so it can be cut into thin sections. The remaining material is mostly collagen.

This slide contains two samples:

• Long Bone - partial cross-section from the end of a long bone found in the extremities.
• Flat Bone - cross-section of a bone from the skull cap (calvarium).

Most bones contain both compact and spongy bone.

Two structural arrangements of bone tissue are seen:

• Compact Bone - a dense layer that forms the outer shell or cortex of bones.
  • Long Bone - forms the outer circular surface.
  • Flat Bone - forms the outer and inner flat surfaces.
• Spongy (Cancellous or Trabecular) bone - anastomosing network of spicules found in the interior of bones.
  • Long Bone - often found near the ends of long bones.
  • Flat Bone - fills the narrow interior of flat bones.

A three-dimensional view of compact and spongy bone is seen in EM 215 Tibia by scanning electron microscopy.