endochondral ossification

Examples of endochondral ossification in the following topics:

• Bone Development

  • Intramembranous ossification stems from fibrous membranes in flat bones, while endochondral ossification stems from long bone cartilage.
  • The development of bone from fibrous membranes is called intramembranous ossification; development from hyaline cartilage is called endochondral ossification.
  • Endochondral ossification is the process of bone development from hyaline cartilage.
  • All of the bones of the body, except for the flat bones of the skull, mandible, and clavicles, are formed through endochondral ossification .
  • Endochondral ossification is the process of bone development from hyaline cartilage.

• Embryonic and Fetal Bone Formation

  • During fetal development, bone tissue is created through intramembranous ossification and endochondral ossification.
  • As development proceeds down the body axis, the long bones of the arms and legs are produced by endochondral ossification.
  • Unlike the other process of bone creation— endochondral ossification—intramembranous ossification does not involve cartilage.
  • Endochondral ossification is the other essential bone creation process during fetal development of the mammalian skeletal system.
  • Unlike intramembranous ossification, cartilage is present during endochondral ossification.

• Development of the Skeleton

  • Early in gestation, a fetus has a cartilaginous skeleton that becomes bone in the gradual process of endochondral ossification.
  • Early in gestation, a fetus has a cartilaginous skeleton from which the long bones and most other bones gradually form throughout development and for years after birth in a process called endochondral ossification.
  • Intramembranous ossification is the direct laying of bone into the primitive connective tissue (mesenchyme).
  • Endochondral ossification involves cartilage as a precursor.
  • Chondrocytes in the primary center of ossification begin to grow (hypertrophy).

• Stages of Bone Development

  • Although bone initially forms during fetal development, it undergoes secondary ossification after birth and is remodeled throughout life.
  • The formation of bone during the fetal stage of development occurs by two processes: intramembranous ossification and endochondral ossification.
  • The steps in intramembranous ossification are:
  • Endochondral ossification begins with points in the cartilage called "primary ossification centers."
  • They mostly appear during fetal development, though a few short bones begin their primary ossification after birth.

• Postnatal Bone Growth

  • Secondary ossification occurs after birth at the epiphyses of long bones and continues until skeletal maturity.
  • Secondary ossification occurs after birth.
  • During postnatal bone formation, endochondral ossification initiates bone deposition by first generating a structural framework at the ends of long bones, within which the osteoblasts can synthesize a new bone matrix.
  • Zone of bone deposition (ossification): The walls between the lacunae break down and the chondrocytes die.
  • Differentiate among the zones of development from cartilage to bone in postnatal ossification

• Cartilage Growth

  • This temporary cartilage is gradually replaced by bone (endochondral ossification), a process that ends at puberty.

• Bone Repair

  • The replacement process is known as endochondral ossification with respect to the hyaline cartilage and bony substitution with respect to the woven bone.

• Capacity of Different Tissues for Repair

  • The replacement process is known as endochondral ossification with respect to the hyaline cartilage and bony substitution with respect to the woven bone.

• Growth of Bone

  • It is a layer of hyaline cartilage where ossification occurs in immature bones.
  • The newly-deposited bone tissue at the top of the zone of ossification is called the primary spongiosa.
  • The older bone at the bottom of the zone of ossification is called the secondary spongiosa.
  • At the same time, osteoblasts via intramembranous ossification, produce new bone tissue beneath the periosteum.
  • The bottom-most row is the zone of ossification which is part of the metaphysis.

• Fontanels

  • The ossification of the bones of the skull causes the fontanelles to close over a period of 18 to 24 months; they eventually form the sutures of the neurocranium.
  • This is called intramembranous ossification.