Bone Development

Introduction

Textbook

Histology and Cell Biology: An Introduction to Pathology, A.L. Kierszenbaum, 2002 - Connective Tissue, Chapter 4 pp118-129; Osteogenesis, Chapter 5 pp131-145

Haversian Systems

• also called osteons
• Volkmann's canals

Lamellae

• concentric
• interstitial
• circumferential

Cells

• osteocytes
• canaliculi

Bone Cells

Osteocytes

• mature bone-forming cells embedded in bone matrix
• derive from osteogenic stem cells forming Osteoblasts
• line surface of bone, secrete organic matrix of bone (osteoid), converted into osteocytes when become embedded in matrix (which calcifies soon after deposition) (Google- osteoblast images)

Osteoclasts

• bone-resorbing multinucleated macrophage-like cells, seal a small segment of extracellular space (between plasma membrane and bone surface), HCl secreted into this space by osteoclasts dissolves calcium phosphate crystals (give bone rigidity and strength) (Google- osteoclast images)
• do not mistake for megakaryocytes, found in bone marrow not associated with bone matrix.

Bone Matrix

The bone matrix has 2 major components. Organic portion composed of mainly collagen Type 1 (about 95%) and amorphous ground substance. Inorganic portion (50% dry weight of the matrix) composed of hydroxyapatite crystals, calcium, phosphorus, bicarbonate, nitrate, Mg, K, Na. (Google- bone matrix images)

Links

• Original class notes
• UNSW Virtual Slidebox Virtual Slidebox Phase 1
• Virtual Slidebox of Histology (USA) Skeletal system

Other Textbooks

• Anatomy of the Human Body (H. Gray, 1918.)Osteology
• Molecular Biology of the CellBone Is Continually Remodeled by the Cells Within ItImage: Figure 22-52. Deposition of bone matrix by osteoblasts.Image: Figure 22-56. The development of a long bone.
• Molecular Cell BiologyMutations in Collagen Reveal Aspects of Its Structure and Biosynthesis
• The Cell- A Molecular ApproachSteroid Hormones and the Steroid Receptor Superfamily
• Clinical Methods: The History, Physical, and Laboratory Examinations100. Alkaline Phosphatase and Gamma Glutamyltransferase
• Endocrinology: An Integrated Approach by Nussey, S.S. and Whitehead, S.A. Endocrinology: Definition and causes of osteoporosis
• Developmental Biology 6th ed. by Gilbert, Scott F. Aging: The Biology of Senescence