Bone Development

Ossification

The biological process during which bone is formed from mesenchymal tissues.

Intramembranous Ossification

A type of ossification where mesenchymal tissue is directly converted into bone, primarily occurring in flat bones.

Endochondral Ossification

The process where cartilage is replaced by bone, responsible for the formation of long bones.

Mesenchymal Tissue

A type of tissue that differentiates into various types of cells, including those that form bones.

Flat Bones

Bones that are characterized by a flat shape, such as those found in the skull.

Osteoprogenitor Cells

Precursor cells that differentiate into osteoblasts, responsible for bone formation.

Osteoblasts

Bone-forming cells that create the bone matrix and spicules.

Osteocytes

Mature bone cells that result from osteoblasts becoming trapped in the matrix they produce.

Osteoclasts

Cells that break down bone, working alongside osteoblasts to remodel bone.

Hyaline Cartilage

A type of cartilage that serves as a temporary model for bone structure during endochondral ossification.

Epiphyseal Plates

Cartilaginous areas that allow for growth during development in long bones.

Medullary Cavity

The central cavity of a long bone where bone marrow is stored.

Primary Ossification Center

The region where blood vessels invade the diaphysis and osteoblasts begin laying down spongy bone.

Secondary Ossification Centers

Regions in the epiphyses where spongy bone is formed after the primary ossification.

Trabeculae

Small, lattice-like structures that form spongy bone.

Fontanelles

Soft spots on an infant's skull that allow for flexibility during childbirth.

Periosteum

A layer of connective tissue that covers the surface of bones and is involved in bone formation.

Articular Cartilage

Cartilage that provides cushioning at joints.