Hyper-secretion of hGH in childhood causes increased length of long bones, very tall children 3. Hyper-secretion of hGH after puberty results in bone thickening in regions of hands, feet, jaw, skull, etc. A comparison of bone growth by Intramembranous Ossification vs. Endochondral Ossification . . . . . Growth of cartilage model Mesenchyme - differentiates into osteoprogenitors, osteoblasts . . . Nutrient artery stimulates bone formation in periosteal region Osteoblasts form spongy bone . . .
Spongy bone grows outward . . .
Formation of primary ossification center spongy bone replaces cartilage interior Periosteum developed . . . . Osteoclasts form marrow cavity . . . . Bone grows outward in two directions . . . .