What is the Haversian system and how is it visualized?

I. The Haversian system is the structural unit of bone tissue composed of the Haversian canal, lacunae occupied by osteocytes, and lamellae.

II. The Haversian system is visualized only in mature bone tissue, that is, one that is already well structured and calcified.

III. The Haversian system is composed of Volkmann's canals, which are delicate tunnels within the bone that contain blood vessels and communicate with neighboring Haversian systems.

IV. The Haversian system is visualized in decalcified bone, but it is more difficult to see.