The concentric rings of cells that compact bone forms surrounding central canals are called osteons or Haversian systems.
Each osteon is essentially a cylindrical structure that consists of a central canal, known as the Haversian canal, where blood vessels and nerves run. This canal is surrounded by layers of bone matrix called lamellae. The lamellae are organized in concentric circles around the central canal, providing strength and support to the bone. Between these lamellae are small spaces called lacunae, which house the bone cells known as osteocytes.
This arrangement allows for efficient nutrient exchange and communication between the osteocytes through tiny channels called canaliculi. The structure of osteons enables compact bone to withstand various stresses and contributes to the overall resilience of the skeletal system.