تبقى الosteoclast عود من يصيرلي واهس 😂🌚

In healthy adults, about 5% to 10% of bone is turned over [renewed] annually

The antibiotic tetracycline is a uorescent molecule that binds newly deposited osteoid matrix during mineralization with high af nity and speci cally labels new bone under the UV microscope (Figure 8–12). This discovery led to methods for measuring the rate of bone growth, an
important parameter in the diagnosis of certain bone disorders. In one technique tetracycline is administered twice to patients, with an intervening interval of
11-14 days. A bone biopsy is then performed, sectioned without decalci cation, and examined. Bone formed while tetracycline was present appears as uorescent lamellae and the distance between the labeled layers is proportion- al to the rate of bone appositional growth. This procedure is of diagnostic importance in such diseases as osteo- malacia, in which mineralization is impaired, and osteitis brosa cystica, in which increased osteoclast activity results in removal of bone matrix and brous degeneration

هلمعلومة برة الموضوع... بس حبيت

Osteoclast

Howship lacunae

والانزيمات هي Cathepsin K & collagenase

أما انواع العظم اللي هي...
woven bone & lamellar bone

lamellar bone

P: Volkmann canals
I : Interstitial lamellae

Osteogenesis :

هو شوف بقالي الendochondral ossification بس مبية حيل