What type of lamellae wrap around each osteon?

• A. Circumferential
• B. Concentric
• C. Interstitial
• D. Perforating

Answer: (B)

The question is about the structure of an osteon. A key feature of each osteon is the central Haversian canal, around which the tissue is arranged in concentric rings. These concentric lamellae form a series of circular layers that wrap directly around that central canal, creating the cylindrical, weight-bearing unit of compact bone. The alternating fiber directions in successive lamellae give the osteon greater strength and resistance to twisting.

Other lamellae types exist but don’t wrap around each osteon the way concentric lamellae do: circumferential lamellae run around the outer surface of the bone, interstitial lamellae are remnants between osteons, and perforating lamellae run perpendicular to osteons to connect them.