THE ARRANGEMENT OF HAVERSIAN SYSTEMS IN A DIAPHYSIS – 1
The diagram shows the arrangement of lamellar bone in a diaphysis, when observed in cross-section. As seen on the previous page, the Haversian systems of the diaphysis of long bones are arranged one above the other, forming thousands of columns each measuring a few centimeters long.
These Haversian systems, or osteons, run along the vertical axis of the bone.
The diagram shows a small segment of a ring obtained by a cross-section of a diaphysis. Observe that the spaces between Haversian systems are filled with groups of flat or sligthly curved bone lamellae.
Four Haversian systems can be observed in the figure, highlighted in different shades of blue. The central canal of each Haversian system, called the Haversian canal, contains blood vessels, lymphatics, and nerves.
The blood vessels that run inside the Haversian canals communicate with blood vessels thatplaced transversely in the diaphysis within tunnels called Volkmann’s canals. Most of these blood vessels are branches of the vessels placed in the medullary canal (on the right in the figure) or, in a smaller amount, by vessels of the periosteum the enter the bone trough small orifices.
Volkmann’s canals connect adjacent Haversian canals and build a complex system of blood circulation in the compact bone.
The vessels placed within the Haversian canal allow blood and lymphatic circulation to travel the length of each Haversian system and are responsible for nourishing the osteocytes of each osteon.
These Haversian systems, or osteons, run along the vertical axis of the bone.
The diagram shows a small segment of a ring obtained by a cross-section of a diaphysis. Observe that the spaces between Haversian systems are filled with groups of flat or sligthly curved bone lamellae.
Four Haversian systems can be observed in the figure, highlighted in different shades of blue. The central canal of each Haversian system, called the Haversian canal, contains blood vessels, lymphatics, and nerves.
The blood vessels that run inside the Haversian canals communicate with blood vessels thatplaced transversely in the diaphysis within tunnels called Volkmann’s canals. Most of these blood vessels are branches of the vessels placed in the medullary canal (on the right in the figure) or, in a smaller amount, by vessels of the periosteum the enter the bone trough small orifices.
Volkmann’s canals connect adjacent Haversian canals and build a complex system of blood circulation in the compact bone.
The vessels placed within the Haversian canal allow blood and lymphatic circulation to travel the length of each Haversian system and are responsible for nourishing the osteocytes of each osteon.
