BIOL 319 Exam 2: Layers of the Epiphyseal Plate

What is the zone after the zone of reserve cartilage?

zone of hyperplasia: also known as the zone of proliferation or growth zone

What is hyperplasia?

increase in number of cells

What happens in the zone of hyperplasia?

interstitial division: forms columns of chondrocytes in lacunae

What is the next zone after the zone of proliferation?

zone of hypertrophy: where primary ossification starts

What happens in the zone of hypertrophy?

chondrocytes get larger as well as their lacunae

about to apoptosis

What is the zone after the zone of hypertrophy?

zone of calcification: chondrocytes make calcified coffin and start dying

How thick is the epiphyseal plate?

3 zones thick: resting cartilage, proliferation, hypertrophy

soft tissue

Is the zone of calcification bone?

no: deadened cartilage

What zone is after the zone of calcification?

zone of ossification: osteoblasts and clasts converting graveyard into new bone

Where are osteoblasts and clasts working in the zone of ossification?

border of diaphysis

Where is the proximal epiphyseal plate located?

close to trunk of the body

Where is the distal epiphyseal plate located?

further from trunk of the body

What is appositional growth?

growing bone wide

What 2 things has to occur when bone widens?

thicken diaphyseal wall

widen the medullary cavity 

What is bone remodeling?

destruction and construction harmonizing in bone

Who are the builders and destroyers of bone?

builders: osteoblasts

destroyers: osteoclasts