6.6 Bone growth Flashcards
what are the 3 types of bone growth?
length, articular cartilage, width
how does bone grow in length
via hyaline cartilage at epiphyseal plate
how does bone growth in length begin?
interstitial cartilage growth followed by appositional cartilage growth
what are the 4 zones of bone growth (for length)
resting cartilage
proliferation
hypertrophy
calcification
what happens to the epiphyseal plate during bone growth in length?
it remains the same width
what is the zone of resting cartilage?
area of the epiphyseal plate nearest the epiphysis
has randomly arranged condrocytes that do not divide rapidly
what is the zone of proliferation?
the area of the epiphyseal plate that produces new cartilage through interstitial growth
condrocytes divide and form columns
what is the zone of hypertrophy?
the condrocytes formed in the zone of proliferation mature and enlarge
what is the zone of calcification?
hypertrophied condrocytes die after surrounding themselves with calcified cartilage
this is then changed to bone
why is there growth at articular cartilage?
so the epiphysis can grown in size
what types of bones experience growth at the articular cartilage most often?
bones that do not have an epiphysis like short bones
how does bone growth occur at the articular cartilage?
much like at the epiphyseal plate
does all growth at the articular cartilage become ossified?, like in the epiphyseal plate/line?
no, articular cartilage remains
describe bone growth in width
via appositional growth under the periosteum (new bone is added to outside)
osteoblasts under the periosteum lay down matrix in a ridge formations
Ridges get enhanced and the grooves deepen until they eventually form a tunnel around blood vessels and endosteum
concentric lamellar layers are added by osteoblasts to form an osteon
circumferential and interstitial lamellae are added prn
Whaat are2 factors that can affect bone growth?
nutrition
Hormones
