What is the structural unit of compact bone called?

The structural unit of compact bone is known as the osteon. Osteons, also referred to as Haversian systems, are cylindrical structures that are composed of concentric layers of mineralized matrix organized around a central Haversian canal, which contains blood vessels and nerves. This arrangement allows for efficient nutrient delivery and waste removal for the bone cells, contributing to the bone's strength and resilience.

Within the osteon, specialized bone cells such as osteoblasts, which are responsible for bone formation, and osteoclasts, which are involved in bone resorption, can be found, but they are not the main structural unit themselves. Chondrocytes are cells found in cartilage rather than bone. Thus, the osteon is the key structural element that defines the microarchitecture of compact bone, making it crucial for maintaining overall bone health and function.