111314 OSSEOUS TISSUE ORGANIZATION Bone Osseous Tissue Characteristics

11/13/14 OSSEOUS TISSUE ORGANIZATION

Bone (Osseous) Tissue Characteristics • Dense matrix, supportive connective tissue • Majority is solid matrix of calcium phosphate, Ca 3(PO 4)2 • Around collagen fibers (approx. 25% collagen) • Osteocytes within lacunae organized around blood vessels

Organization of Compact Bone Tissue • Osteon is basic unit of mature compact bone • Osteocytes are arranged in concentric lamellae • Around a central canal (Haversian canal) containing blood vessels

Perforating Canals • Also called horizontal canals or Volkmann’s canals) • Perpendicular to the central canal • Carry blood vessels into bone and marrow Concentric Lamellae (plate-like membrane) • wrapped around the entire long bone • Binds osteons together

Compact bone layers reminder: Periosteum • Outside covering of all bones except parts enclosed in joint capsules • Peri = around (ex: perimeter)

Endosteum – Lines the marrow cavity and lines the central canals - Endo = inside (ex: endoskeleton)

Organization of Spongy Bone Tissue • No organized osteons • The matrix consists of trabeculae which are strands of bone that make up an irregular “meshwork” / “lattice work” with spaces

• The space between trabeculae is filled with red bone marrow: – Which forms red blood cells and supplies nutrients to osteocytes • In some bones, spongy bone holds yellow bone marrow (stores fat)