Bone formation (ossification/osteogenesis) and growth Flashcards
How does the medullary cavity enlarge during growth in thickness?
Osteoclasts destroy the bone tissue lining the medullary cavity enabling it to enlarge as the bone increases in thickness.
Where does the growth in length of a bone occur?
At the epiphyseal growth plate
What zone (within the epiphyseal plate) is nearest the epiphysis, consists of small scattered chondrocytes and does NOT function in bone growth (anchors the epiphyseal plate to the epiphysis of the bone)?
Zone of resting cartilage
What zone consists of slightly larger chondrocytes arranged like stacks of coins and undergoes institual growth as they divide and secrete ECM?
Zone of proliferating cartilage
What zone has large, maturing chondrocytes arranged in columns?
Zone of hypertrophic cartilage
What zone is only a few cells thick and is mostly dead chondrocytes (ECM around them has calcified)?
Zone of calcified cartilage (nearest to diaphysis)
What occurs on the epiphyseal side of the epiphyseal plate during growth in length?
Interstitial growth of cartilage via mitosis: chondrocytes proliferate
What occurs on the diaphyseal side of the epiphyseal plate during growth in length?
Replacement of cartilage of the plate by bone: osteoblasts dissolve calcified cartilage and osteoblasts build bone
Which part of the long bone increases in length?
Diaphysis
Which part of the bone enlarges as bone increases in thickness?
Medullary cavity
Does healing occur faster in bone or cartilage? Why?
Healing is faster in bone than in cartilage because there are no blood vessels in cartilage.