Assertion: periosteum's osteoblast | /r/CapableOf | form spongy bone
Facets:
value: internally
type: LOCATION
value: at primary ossification centers
type: LOCATION
Source sentences:
text: Blood vessels and osteoblasts from the periosteum invade the calcified cartilage template; internally, these osteoblasts form spongy bone at primary ossification centers (and later secondary ossification centers); externally, the periosteal osteoblasts form compact bone.
text: The remaining bits are covered with bone matrix by osteoblasts forming spongy bone.