Light micrograph of compact bone belonging to a cross-sectioned long bone diaphysis, stained with the Schmorl technique. A variant of this technique has been used that stains the somas and fine processes of osteocytes reddish. Osteons are clearly identified, being the essential components of compact bone tissue. They correspond to rounded or oval structures, made up of bony lamellae arranged concentrically around a small duct (Haversian duct), occupied by a small blood vessel. Between the lamellae are the oval bodies of the osteocytes, from which numerous and fine extensions come into contact with each other, forming a complex labyrinth. Among the osteons there are groupings of bone lamellae called interstitial lamellae.