Bone tissue is primarily composed of what structural unit?

Bone tissue is primarily composed of osteons, also known as Haversian systems. Osteons are the fundamental structural units of compact bone and consist of a central canal surrounded by concentric layers of bone matrix and osteocytes, which are mature bone cells. Each osteon provides support and strength to bone tissue, allowing it to withstand various stresses and strains.

The central canal within an osteon contains blood vessels and nerves, facilitating the nourishment and signaling necessary for bone maintenance and health. The arrangement of osteons in bone tissue allows for effective load distribution and contributes to the overall integrity of the skeletal system. This organization is crucial for functions such as movement, support, and protection of internal organs.

Osteocytes, while integral to bone structure, are not the primary structural unit on their own; they reside within the osteons. Similarly, sarcomeres and myofibrils are components associated with muscle tissue, not bone tissue, and therefore do not pertain to the composition of bone.