Question

Answer each with a few sentences please:

1. Epiphyseal plate function and increase in length of a long bone

2. Osteoclast functions in bone ECM degradation

3. Cells in the osteogenic periosteum and what they do

4. Comparison of osteogenic and chondrogenic stem cells

Answer 1

1) The epiphyseal plate is the region of development in a long bone. It is a layer of hyaline cartilage where ossification occurs in immature bones. On the epiphyseal side of the epiphyseal plate, cartilage is formed. It separates the epiphysis from the diaphysis and diaphyseal side, cartilage is ossified and the diaphysis help in the growth in length of bone.

2) Osteoclasts are specialized multinucleated giant cells, which reabsorb bone. This is carried out due to the process of remodelling of extracellular matrix. The osteoclasts are cell capable of bone degradation. Extracellular matrix is continuously remodelled by the activities of the osteoclasts, which degrade the bone matrix, and the osteoblasts, which deposit it. An imbalance between reabsorbing and deposition underlies diseases where in bone density is modified, which includes osteopetrosis and osteopenia and osteoporosis.

3) The osteogenic periosteum is a connective tissue, which supports bone health and development. It is a membrane, which covers the outer surface of all bones, except at the joints of long bones. The thin tissue has two layers, which act in different ways. The outer layer is the fibrous periosteum, acts for attachment of muscle tissue to the bone and provides pathways for blood and lymphatic tissues.

The inner layer is cambium layer, which contains progenitor cells that develop into osteoblasts. These osteoblasts are responsible for increasing the width of a long bone.

4) Stem cells of the osteogenic , which includes both osteoblasts and chondroblasts. They are derived from a stromal stem cell in the postnatal organism. That exist there osteogenic precursors in association with the soft, fibrous tissue of the marrow stroma is well established.

Chondrogenic stem cells are progression of mesenchymal stem cells (MSCs). MSCs appear to be limited to follow an endochondral ossification program, which will end in vascular penetration, marrow deposition and ossification of cartilaginous tissue.