Describe the process of intramembranous ossification

-starts when mesenchymal cells in the center of the region where the bone is about to develop cluster together and differentiate directly into osteoblasts at the primary ossification center -Osteoblast cells then begin to secrete a substance called osteoid, eventually trapping themselves in small cavities called lacunae -The osteoblasts then become osteocytes. -The osteoid secreted by the osteoblasts will accumulate between the embryonic blood vessels in the region, forming bone with a sponge-like appearance. -On the edges of the spongy, woven bone,mesenchyme will condense to form the periosteum(outermost layer of the bone) -Directly adjacent to the periosteum the trabeculae will thicken and be replaced by lamellar bone to form a compact layer of bone b/n the outer periosteal and inner trabecular portions of the bone - The trabecular on the inside do not change, and are referred to as the diploe of the flat bones. Blood vessels remaining in the trabeculae later become the red marrow