HAVERSIAN SYSTEMS OR OSTEONS – 1
The arrangement of concentric curved lamellae constituting tunnels constitutes a type of mature bone that forms the majority of the bones 0f the body, especially in the diaphyses. This type of arrangement is called a Haversian system or an osteon.
The Haversian systems measure about 0.2–0.4 mm in diameter and a few millimeters long. The tunnel situated in the Haversian canal or osteonal canal runs in the center of each Haversian system. The Haversian canal contains blood vessels, lymphatic vessels, and nerves.
The osteocytes of each osteon are placed between the bone lamellae and are nourished by the bone canaliculi that open into the Haversian canal placed at the center of the system. The inner surface of the Haversian canal is lined with osteoblasts, as any other bone surface.
The Haversian systems measure about 0.2–0.4 mm in diameter and a few millimeters long. The tunnel situated in the Haversian canal or osteonal canal runs in the center of each Haversian system. The Haversian canal contains blood vessels, lymphatic vessels, and nerves.
The osteocytes of each osteon are placed between the bone lamellae and are nourished by the bone canaliculi that open into the Haversian canal placed at the center of the system. The inner surface of the Haversian canal is lined with osteoblasts, as any other bone surface.
Top image
Schematic drawing of a Haversian system constituted by three concentric curved lamellae.
Bottom image
The lamellae of the Haversian system are formed by collagen fibers arranged in parallel. Observe how the directions of the fibers differ from one lamella to the other. This arrangement offers great resistance towards mechanical pressure and torsion.
