What is the structural unit that makes up bone?

The structural unit that makes up bone is referred to as an osteon. An osteon, also known as a Haversian system, is the fundamental functional unit of compact bone. It consists of a central canal surrounded by concentric layers of calcified matrix called lamellae. The central canal contains blood vessels and nerves, which are essential for the nourishment and maintenance of bone tissue.

Osteocytes, while significant in bone maintenance, are mature bone cells embedded within the bone matrix but do not constitute the primary structural unit. Chondrocytes are the cells found in cartilage and are not involved in the structure of bone. Ligaments primarily connect bone to other bones and are made of connective tissue, rather than forming the structural framework of bone itself. Understanding the role of osteons is key to comprehending how bones are structured and function within the human body.