Microscopic Structure of Compact Bone

The Osteon • Compact bone is made of multiple osteons – Osteons are made of concentric rings of matrix called lamellae.

Osteocytes • Osteocytes(bone cells) live in spaces within the lamellae. These spaces are called lacunae.

The Matrix • Calcium Carbonate and Calcium Phosphate form mineral crystals called hydoxyapatite.

Blood Flow to the Osteocytes • • Blood enters to the bone by arterioles through the nutrient foramina.

Blood also enters the bone through periosteal

blood vessels.

– Blood then travels through the Haversian canals. These run through the center of the osteon.

– Haversian canals are connected laterally through Volkman’s canals.

– The smallest canals connecting all osteocytes are called canaliculi.

Blood Flow to the Osteocytes

Review 1. What is the functional unit of compact bone called?

Review 1. What is the functional unit of compact bone called?

The Osteon

Review 2. “Bone cells” live within the “spaces” found between the “rings” of the osteon What are these three structures called?

Review 2. “Bone cells” live within the “spaces” found between the “rings” of the osteon What are these three structures called?

Bone Cells=Osteocytes Spaces =lacunae Rings= lamellae

Review 3. Place the following blood vessels or canals in order from largest to smallest Volkman’s canals Canaliculi Haversian Canals

Review 3. Place the following blood vessels or canals in order from largest to smallest Haversian Canals Volkman’s Canals Canaliculi