What are the stages of bone development?
Bone development occurs in 3 stages, intramembranous ossification, endochondral ossification, and then remodeling.
What is the most common type of bone development?
For skeletal development, the most common template is cartilage. During fetal development, a framework is laid down that determines where bones will form. This framework is a flexible, semi-solid matrix produced by chondroblasts and consists of hyaluronic acid, chondroitin sulfate, collagen fibers, and water.
What is the development of bones called?
The terms osteogenesis and ossification are often used synonymously to indicate the process of bone formation.
What is the difference between the two types of bone formation?
All bone formation is a replacement process. During development, tissues are replaced by bone during the ossification process. In intramembranous ossification, bone develops directly from sheets of mesenchymal connective tissue. In endochondral ossification, bone develops by replacing hyaline cartilage.
What is the major difference of intramembranous and endochondral ossification?
In endochondral bones, ossification occurs within the cartilaginous template and also within the surrounding fibroblastic perichondral sheath to form the bone collar. Intramembranous bones develop via direct osteoblast differentiation within the mesenchyme.
What's the difference between endochondral and intramembranous ossification?
In intramembranous ossification, bone develops directly from sheets of mesenchymal connective tissue. In endochondral ossification, bone develops by replacing hyaline cartilage. Activity in the epiphyseal plate enables bones to grow in length.
How do bones develop and grow?
A growing bone lengthens when cells in its so-called growth plate, a region at the ends of growing bones, multiply and expand. The cells, called chondrocytes, form the cartilage that provides a scaffold for the mature calcified bone that later grows on top of them.
What do most bones develop from?
Bone development begins with the replacement of collagenous mesenchymal tissue by bone. Generally, bone is formed by endochondral or intramembranous ossification. Intramembranous ossification is essential in the bone such as skull, facial bones, and pelvis which MSCs directly differentiate to osteoblasts.
What is the difference between ossification and calcification?
In pathological calcification, calcium salts are deposited in normal (metastatic calcification) or damaged (dystrophic calcification) tissue, whereas the term 'ossification' implies bone formation (calcification in a collagen matrix) (Chan et al. 2002).
Why is bone development important?
Maximizing a child's genetic potential for peak bone mass is important because it is estimated that a 10% increase in peak bone mass would delay the development of osteoporosis by 13 years.
What's the meaning of ossification?
the natural process of bone formation1a : the natural process of bone formation. b : the hardening (as of muscular tissue) into a bony substance. 2 : a mass or particle of ossified tissue. 3 : a tendency toward or state of being molded into a rigid, conventional, sterile, or unimaginative condition.
Which bone is developed by endochondral ossification?
Endochondral ossification is the mechanism responsible for the formation of all long bones of the axial skeleton (vertebrae and ribs) and the appendicular skeleton (limbs).
What type of bone does endochondral ossification form?
Endochondral ossification is the mechanism responsible for the formation of all long bones of the axial skeleton (vertebrae and ribs) and the appendicular skeleton (limbs).
Which bones undergo 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.
What is the difference between appositional and interstitial growth?
Appositional growth occurs when chondroblasts secrete new matrix along existing surfaces and this causes the cartilage to expand and widen. In interstitial growth, chondrocytes secrete new matrix within the cartilage and this causes it to grow in length.
Is endochondral an ossification?
Endochondral ossification is the process by which bone tissue is formed in early fetal development. It begins when MSCs start to produce a cartilage template of long bones, such as the femur and the tibia, upon which bone morphogenesis occurs.
Abstract
Bone grows in two ways in humans (and mammals, as well as other related animals). In enchondral bone growth, bone arises from columns of cartilage cells in growth plates which undergo a well-defined sequence of activities and changes in morphology.
Keywords
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How do bones grow in length?
It is a layer of hyaline cartilage where ossification occurs in immature bones. On the epiphyseal side of the epiphyseal plate, cartilage is formed. On the diaphyseal side, cartilage is ossified, and the diaphysis grows in length.
What is bone tissue?
Bone is a replacement tissue; that is, it uses a model tissue on which to lay down its mineral matrix. For skeletal development, the most common template is cartilage. During fetal development, a framework is laid down that determines where bones will form. This framework is a flexible, semi-solid matrix produced by chondroblasts and consists ...
What is the skeleton of an embryo?
In the early stages of embryonic development, the embryo’s skeleton consists of fibrous membranes and hyaline cartilage. By the sixth or seventh week of embryonic life, the actual process of bone development, ossification (osteogenesis), begins. There are two osteogenic pathways—intramembranous ossification and endochondral ossification—but bone is ...
What is the name of the matrix that calcifies and hardens?
The osteoblasts secrete osteoid, uncalcified matrix, which calcifies (hardens) within a few days as mineral salts are deposited on it, thereby entrapping the osteoblasts within. Once entrapped, the osteoblasts become osteocytes ( [link] b ). As osteoblasts transform into osteocytes, osteogenic cells in the surrounding connective tissue differentiate into new osteoblasts.
How are the flat bones of the face formed?
The flat bones of the face, most of the cranial bones, and the clavicles (collarbones) are formed via intramembranous ossification. The process begins when mesenchymal cells in the embryonic skeleton gather together and begin to differentiate into specialized cells ( [link] a ).
Which plate is responsible for longitudinal bone growth?
Longitudinal Bone Growth. The epiphyseal plate is responsible for longitudinal bone growth. The proliferative zone is the next layer toward the diaphysis and contains stacks of slightly larger chondrocytes. It makes new chondrocytes (via mitosis) to replace those that die at the diaphyseal end of the plate.
Which side of the epiphyseal plate is ossified?
On the diaphyseal side, cartilage is ossified, and the diaphysis grows in length. The epiphyseal plate is composed of four zones of cells and activity ( [link] ). The reserve zone is the region closest to the epiphyseal end of the plate and contains small chondrocytes within the matrix.
