Chapter 6: Bone Tissue Flashcards
6 Basic functions of skeletal system
Support
Protection
Assist in movement
Mineral homeostasis
Blood cell production
Triglyceride storage
Structure of long bone
Diaphysis
Epiphyses
Metaphyses
Articular cartilage
Periosteum
Medullary cavity
Endosteum
Diaphysis
The long, cylindrical, main portion of the bone. Also called shaft or body
Epiphyses
The proximal and distal ends of the bone.
Metaphyses
Region between diaphysis and epiphyses. Contains epiphyseal plate in growing bone.
Articular cartilage
Thin layer of hyaline cartilage covering the part of the epiphysis where the bone forms a joint. Reduces friction and absorbs shock. Avascular.
Periosteum
Tough connective tissue sheath and it’s associated blood supply that surrounds the bone. Composed of outer fibrous layer and inner osteogenic layer.
Attached to bone by perforating fibres.
Medullary cavity
Hollow, cylindrical space within the diaphysis that contains yellow bone marrow and blood vessels.
Minimizes weight.
Endosteum
Thin membrane that lines medullary cavity and internal spaces of spongy bone.
Single layer of osteoprogenitor cells and small amount of connective tissue.
Bone tissue extracellular matrix
15% water
30% collagen fibres
55% crystallized mineral salts.
Most abundant mineral is calcium phosphate.
Osteoprogenitor cells
Bone stem cells derived from mesenchyme.
Found in osteogenic layer of periosteum, the Endosteum, and canals that contain blood vessels.
Osteoblasts
Bone building cells. Synthesize and secrete collagen fibres and initiate calcification.
Osteocytes
Mature bone cells. Maintain daily metabolism.
Osteoclasts
Concentrated in the Endosteum. Breaks down bone to release minerals into the body for homeostasis.
Compact bone
Strongest type of bone. Found beneath the periosteum of all bones and makes up bulk of the diaphysis.
Contains osteons.
Osteons
Contains bone lamellae arranged around osteonic canals. Contains concentric bone lamellae
Concentric bone lamellae
Circular plates of mineralized extracellular matrix of increasing diameter. Surrounds blood vessels and nerves.
Part of osteons.
Bone lacunae
Small spaces between concentric bone lamellae. Contains osteocytes.
Bone canaliculi
Small channels that radiate out from the bone lacunae. Filled with ECF and processes of osteocytes.
Interstitial bone lamellae
Areas between neighbouring osteons. Fragments of older osteons that have been partially destroyed.
Circumferential bone lamellae
Arranged around the inner and outer circumference of the diaphysis.
Connected to periosteum by perforating fibres.
Spongy bone
Does not contain osteons. Always located in the interior of bone. Consists of bone lamellae irregularly arranged called bone trabeculae.
Perforating canal
Carries arteries from the periosteum into the bone.
Transverse canals
Transport blood vessels from one osteonic canal to the next.
