What step of what ossification?

dupawuti's version from 2016-03-09 19:12


Question Answer
Development of the ossification center - occurs when mesenchymal cell clusters convert to osteogenic cells, which then convert to osteoblasts that secrete the extracellular matrix of bone.Step 1 of intramembranous ossification
Calcification - occurs when osteoblasts transform to osteocytes, isolated in a lacunae.Step 2 of intramembranous ossification
Formation of trabeculae - occurs when extracellular matrix forms spngy bone and is characterized by many spaces between the trabeculae that are filled with red bone marrow.Step 3 of intramembranous ossification
Development of the periosteum - occurs when periphereal mesenchyme condenses and develops into the periosteum. Eventually, spongy bone is sandwiched between two layers of compact bone.Step 4 of intramembranous ossification
Development of the cartilage model - takes place when mesenchymal cells become chondroblasts that secrete a hyaline cartilage model surrounded by a perichondrium.Step 1 of Endochondrial ossification
Growth of the cartilage model - is a continuation of the matrix being secreted; chondrocytes in the center hypertrophy (grow larger); the matrix begins to calcify so the chondrocytes die, leaving lacunae that fuse into small cavities.Step 2 of Endochondrial ossification
Development of the primary ossification center - begins in the center of the model; the promary ossification center forms where bone tissue will replace cartilage. Osteoblasts secrete bone matrix forming spngy bone. A nutrient artery penetrates the perichondrium and calcifying cartilage. which helps stimulates osteogenic cells in the perichondrium to become osteoblasts. At this point the perichondrium becomes periosteum.Step 3 of Endochondrial ossification
Development of the medullary cavity - begins as the primary ossification center grows toward ends of bone; osteoclasts break down spongy bone to form the medullary cavity in the diaphysis.Step 4 of Endochondrial ossification
Development of the secondary ossification centers - occurs in epiphyses and is stimulated by vascular invasion of epiphyseal arteries around the time of birth. Step 5 of Endochondrial ossification
Formation of articular cartilage and epiphyseal plate - occurs when hyaline cartilage covering epiphyses becomes the articular cartilage. The epiphyseal plate is hyaline cartilage in metaphyses that are responsible for bone growth lengthwise.Step 6 of Endochondrial ossification