KAAP 309 Bones

Functions of bone

support, protection, movements, storage, acid/base balance, hematopoiesis, hormone production

Where is yellow marrow located?

in adult appendicular skeleton

where is red marrow located?

in children and in adult flat, irregular, femur, and humerus

compact bone (cortical)

dense white osseous tissue, surround medullary cavity; dense

spongy bone (cancellous)

internal layer, filled with trabeculae, in epiphysise

endosteum

lines medullary cavity, internal surface is osteogenic

osteoprogenitor cell

stem cells, in endosteum and inner periosteum layers

osteoblasts

bone forming cells, synthesizes osteoid and promotes mineralization

osteocytes

maintenance cells, in lacunae, maintains matrix, majority of bone cells, mature cells

osteoclasts

bone dissolving cells, breaks bones and resorbs minerals; multinucleated

what becomes of osteoblasts?

osteoblasts become engulfed in mineralized matrix and becomes osteocytes

lacuna

houses osteocytes

lamellae

mineralized matrix

central canal

contain neurovascular bundle

osteon

functional unit of bone

perforating canal (volkman)

connects neurovascular bundle and connects other central canal

central canal (haversion)

feeds osteons

role of collagen fibers

change orientation, resists torsional and tensile forces

Spongy bone

no central canals, orientation depends on stress and develops along stress lines

osteoid

unmineralized matrix from osteoblasts