Ch. 7 bone Elongation, Zones of Metaphysis
What is Epiphyseal Plate?
region of transition from cartilage to bone
What is the function of Bone Deposition?
Breakdown of lacuna walls, leaving open channels, death of chondrocytes, deposition by osteoblasts.
What is the function of Cell Proliferation?
Chondrocytes multiplying and lining up in rows of small flattened lacunae
What is the function of Cell Hypertrophy?
Enlargement of chondrocytes and thinning of lacuna walls
What is the epiphyseal line?
Epiphyses close when cartilage is gone, growth is lengthwise
What is appositional growth?
Growth at bone surface, cont. growth in diameter and thickness, lay down matrix in layers parallel to surface, Osteoclasts of endosteum enlarge marrow cavity
What is bone Remodeling?
Occurs throughout life- 10% per year, repairs micro-fractures, releases minerals into blood, reshapes bones in response to use and disuse.
What are the 5 zones of Metaphysis?
Reserve Cartilage Cell Proliferation Cell Hypertrophy Calcification Bone Deposition
What is the function of Reserve Cartilage?
Resting Hyaline cartilage
What is the function of Calcification?
Temporary calcification of cartilage matrix between columns of lacunae
A mature bone remains a metabolically?
active organ, own maintenance of growth and remodeling, exchanging minerals with tissue fluid.
What is Wolff's law of bone?
bone determined by mechanical stresses placed on it. adapt to with stand stresses, remodeling is collaborative and precise action of osteoblasts and osteoclasts.
What is interstitial growth?
growth from within, elongation is the result of cartilage growth within the epiphyseal plate
Epiphyseal plate function?
growth zone, consist of hyaline cartilage
What is Metaphysis?
transition facing the marrow cavity where cartilage is replaced by bone
