What do you call the structural units of compact bone?

The correct term for the structural units of compact bone is indeed the osteons. Osteons, also known as Haversian systems, are the fundamental functional units within compact bone, providing strength and support. Each osteon consists of concentric layers of mineralized bone matrix called lamellae, surrounding a central canal that contains blood vessels and nerves. The organization of osteons allows for efficient distribution of nutrients and waste removal, essential for maintaining healthy bone tissue.

While Haversian systems is an alternate name for osteons, osteons is the more commonly used term in this context. Canaliculi are tiny channels that connect the lacunae (small spaces containing osteocytes) within the bone tissue to each other and to the Haversian canal, facilitating communication and nutrient transfer between osteocytes. Lamellae refer to the layers of bone matrix that compose the osteon but are not the structural units themselves. Thus, the direct identification of osteons as the structural units of compact bone is what's most accurate.