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
The surface of the articular region of long and flat bones is covered by a layer of hyaline cartilage that is stuck to the articular surface called articular cartilage .
The hollow interior of the diaphysis is the medullary canal, occupied in vivo by bone marrow.
Compact bone and spongy bone
The outmost layer of the whole bone, called cortical bone, is made of a very densetype of bone tissue called compact bone. When sections of compact bone are viewed with a microscope, thousands of small cavities can be oberved. The compact bone is very resistant to tension, torsion and mechanical shocks.
The inner space of the epyphysis is surrounded by a layer of compact bone. This space is filled with 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. These spaces are filled in vivo with bone marrow.
Because 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 resistant to mechanical forces.
Lower figure
A higher magnification of spongy and compact bones.
The outer layer of the bone is made of compact bone (in red) and most of the image is occupied by spongy bone. 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. 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