Cylindrical structure with a diameter of 150–300 μm and a length varying from 2 to 10 μm, composed of concentric lamellae of bone surrounding a Haversian canal with a diameter of 50 μm. In this canal nutritive element, nerves, and connective tissue are present. Between the individual osteons and interstitial lamellae, cementing lines are seen. The longitudinal direction of the osteons is parallel to the axis of the bone. Lamellae are birefringent in polarized light because of changing orientation of the collagen fibers. In the trabecular osteon, the lamellae run parallel to the bone marrow interface.
The microscopic unit of compact bone, consisting of a haversian canal and the surrounding lamellae.