In bone histology, the Haversian system (osteon) of compact bone consists of a central Haversian canal surrounded by concentric lamellae and osteocytes in lacunae. Canaliculi serve which function?

• A Connecting Haversian canals to Volkmann's canals for blood vessel passage
• B Forming the scaffold for new lamellar bone during remodelling
• C Containing osteoclasts for bone resorption
• D Providing passageways for osteocyte cell processes to communicate with adjacent osteocytes and the central canal, enabling nutrient/waste exchange ✓

Explanation

Osteocytes are mature bone cells trapped in lacunae within the mineralised matrix. They extend long cytoplasmic processes through tiny channels called canaliculi that radiate outward from each lacuna, forming an interconnected network. These processes communicate via gap junctions with adjacent osteocyte processes and ultimately reach the Haversian canal surface, permitting nutrient and oxygen delivery from the central vascular supply to osteocytes and removal of metabolic waste. Canaliculi are too narrow for blood vessels; Volkmann's canals are larger transverse channels connecting adjacent Haversian canals. Osteoclasts sit in Howship's lacunae on bone surfaces, not in canaliculi.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

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Written and medically reviewed by the StethoPrep medical team.