Which component forms the central passage in an osteon of mature bone?

Which component forms the central passage in an osteon of mature bone?

• A. Central Haversian Canal
• B. Periosteal Layer
• C. Trabecular Spacing
• D. Lacunae

Answer: (A)

In mature bone, the main passage through each osteon is the central canal, also known as the Haversian canal. This vertical tube runs through the center of the osteon and houses blood vessels and nerves that supply the surrounding lamellae and osteocytes connected by canaliculi. The concentric lamellae wrap around this canal, forming the compact bone’s organized, cylindrical unit. The periosteal layer, by contrast, is the bone’s outer fibrous covering, not part of the osteon’s central pathway. Lacunae are the small spaces that contain osteocytes within the lamellae, and while they communicate through canaliculi, they do not constitute the main central passage.

In mature bone, the main passage through each osteon is the central canal, also known as the Haversian canal. This vertical tube runs through the center of the osteon and houses blood vessels and nerves that supply the surrounding lamellae and osteocytes connected by canaliculi. The concentric lamellae wrap around this canal, forming the compact bone’s organized, cylindrical unit. The periosteal layer, by contrast, is the bone’s outer fibrous covering, not part of the osteon’s central pathway. Lacunae are the small spaces that contain osteocytes within the lamellae, and while they communicate through canaliculi, they do not constitute the main central passage.