The bone shown in this page had all its soft tissues removed mechanically and chemically, then washed, left to dry and finally sectioned longitudinally.
Upper figure
Two types of arrangement of bone cells can be watched in the figure.
The outmost layer of the whole bone, called cortical bone, is made of a very dense bone tissue called compact bone. Sections of compact bone viewed with a microscope show thousands of very small spaces. The compact bone is very resistant to tension, torsion and mechanical shocks.
The inner of the bone contains millions of small plates of bone tissue called trabeculae (singular: trabecula) or spicules. The spatial arrangement of the trabeculae creates a large amout of small spaces that can be seen with a naked eye. The spaces are filled in vivo with bone marrow.
Because of the combination of plates and cavities, this type of bone is called spongy bone or cancellous or trabecular bone.
The trabeculae of the spongy bone are arranged according to the lines of force acting on the bone, turning the spongy bone lighter than the compact bone, although also resistant to mechanical forces.
Lower figure
A higher magnification of spongy and compact bone.
The outer layer of the bone is formed by compact bone (in red). Most of the image is occupied by spongy bone formed by bone trabeculae.
After placing the mouse cursor over the image or clicking on the image: the light pink areas are surfaces of bone trabeculae. The dark red areas indicate lacunae between trabeculae. The arrows point to trabeculae. Cross-sections of trabecullae observed with a microscope appear as lines or rods.
Macrophotograph of a dry bone.
Macrophotograph of a dry bone.
NAVIGATION ON MOL