Exam 3- Bone Flashcards
ECM
Hard and Calcified (mineralized)
Bone
Rigid, supportive & protective
Inorganic Salts
hydroxyapatite: Crystals of Ca and P
(slender, needlelike crystals)
(oriented to resist stress)
Other Minerals in Bone Matrix
Mg, Na, S, and Fl
Organic Matrix (of bone)
Collagen fibers Ground substance (composed of proteins and polysaccharides, secreted by osteroblasts)
Osteoblasts
Bone building cells, small, found in all bone surface. Sythesize and secrete osteoid. Collagen in the osteoid provide a framework for the deposition of hydroxyapatite.
Osteocytes
Mature, nondividing osteroblasts. Lie within the lacunae. Responsible for the erosion of bone minerals, contains large numbers of lysosomes
Compact Bone
Composed of cylinder shapes units called osteons
Central Canal
Extend lengthwise through the osteon, contains blood vessels, connected by transverse canals
Lamellae
Layers (rings) of calcified matrix (between lacunae) Concentric, interstitial (in between rings), circumferential
Lacunae
Small Spaces containing cells
Osteoclasts
Giant, multi-nucleated cells. Responsible for the erosion of bone minerals, contains large numbers of lysosomes
Canaliculi
ultra-small canals connecting lacunae
Cancellous Bone
Spongy bone. Formed by trabeculae. Beams of bony tissue. No osteons. Arranged along lines of stress
Bone Marrow Characteristics
Myeloid Tissue- soft, diffuse connective tissue. Site for Hematopoiesis, contain hematopoietic stem cells.
