Principles of Anatomy and Physiology: Chapter 6: Bone Tissue Flashcards

Forms most of the skeleton, the framework that supports and protects out organs and allows us to move

• Provide support of soft tissues & attachment sites for muscles, creating a framework for the body
• Protection from injury is afforded to internal organs by bones which overlie and/or surround them
• Movement is facilitated since bone provide leverage for muscle contraction
• Mineral homeostasis (calcium & phosphorus) occurs as minerals are stored in bones and can be mobilized when needed elsewhere in the body
• Blood cell production occurs in the red bone marrow formed in certain bones
• Storage of energy occurs in the lipids found in yellow bone marrow

• Cartilage
• Bone
• Bone marrow
• Periosteum

• Diaphysis (shaft)
• Epiphyses (ends)
• Metaphysis
• Articular cartilage
• Periosteum
• Medullary (marrow) cavity
• Endosteum

Widely separated cells surrounded by large amounts of matrix

• Osteoprogenitor cells
• Osteoblasts
• Osteocytes
• Osteoclasts

• Abundant mineral salts (hydroxyapatite)
• Calcium carbonates
• Calcification/mineralization
• Mineral salts confer hardness on bone while collagen fibers give bone its great tensile strength

Compact or spongy bone

• Osteons (Haversian systems) with little spaces between them
• Lies over spongy bone & composes most of the bone tissue of the diaphysis
• Functionally, protects, supports, and resists stress

• Does not contain osteons
• Contains trabeculae surrounding many red marrow-filled spaces
• Forms most of the structure of short, flat, and irregular bones, and epiphyses of long bones
• Functionally, stores red marrow and provides some support

Needed to supply the various bone tissues with bone nutrients and wast disposal through a number of interconnective canals in the bone matrix

• The nutrient artery passing through the nutrient canal and sends branches into the central Haversian canals to provide for osteocytes
• Artery continues into the medullae to supply blood for the marrow and osteocells via the epiphyseal artery
• The periosteal arteries pass through Volkman's canals to a multitude of vessels that supply the outer compact bone region

Sense damage and transmits pain messages

Ossification (osteogenesis)

• Undergo cell division
• Give rise to cells that differentiate into osteoblasts and osteoclasts

During the sixth or seventh weeks of embryonic life and continues throughout adulthood

• Intramembranous ossification
• Endochondral (intracartilaginous) ossification

• Within fibrous membranes of the embryo and the adult
• Ossification centers forms frommesenchymal cells as they convert to osteoblasts and lay down osteoid matrix
• Matrix surrounds the cell and then calcifies as the osteoblast becomes an osteocyte
• The calcifying matrix centers join to form bridges of trabeculae that constitute spongy bone with red marrow between
• The periosteum first forms a collar of spongy bone that is then replaced by compact bone

• The formation of bone with a hyaline cartilage model
• The primary ossification center of a long bone is in the diaphysis
• Cartilage degenerates, leaving cavities that merge to form the medullary cavity
• Osteoblasts lay down bone
• Sedondary ossication centers develop in the epiphyses, where bone replaces cartilage, except for the epiphyseal plate

• The zone of resting cartilage
• The zone of proliferating cartilage
• The zone of hypertrophic cartilage
• The zone of calcified cartilage

The diaphysis of a bone increases in length by intersitial growth

Intersitial and appositional addition of new bone tissue by osteoblasts around the outer surface of the bone and to a lesser extent internal bone dissolution by osteoclasts in the bone cavity

Bone deposition and changes during growth, in addition to thyroid hormone, parathyroid hormone, and calcitonin

Either gigantism or dwarfism

Sudden growth and modifications of the skeleton to create the male and female forms

Ongoing replacement of old bone tissue by new bone tissue

Osteoclasts

Osteoblasts

Any break in bone

• Fracture hematoma
• Procallus
• Conversion of the fibricartilaginous callus into the spongy bone of a bony (hard) callus
• Remodeling of the callus to nearly original form

Formation of a clot

Organization of the fracture hematoma into granulation tissue

• Partial
• Complete
• Closed (simple)
• Open (compound)
• Comminuted
• Greenstick
• Spiral
• Transverse
• Impacted
• Displaced
• Non-displaced
• Stress
• Pathologic
• Pott's
• Colles'

Calcium

Calcium's importance in cardiac, nerve, enzyme, and blood physiology

Parathyroid hormone (PTH)

Calcitonin (CT)

Increasing deposition of mineral salts and production of collagen fibers

Demineralizing (loss of bone minerals) and collagen reduction

Help build and retain bone mass

Loss of calcium and other minerals from bone matrix (demineralization), which may result in osteoporosis

Decreased rate of protein synthesis, resulting in decreased production of matrix components (mostly collagen) and making bone more susceptible to fracture

Limb buds

Hand and foot plates, which will become hands and feet

Flexible rod of tissue that lies in a position where the future vertebral column will develop

Decreased in the amount & strength of bone tissue owing to decrease in hormone output and bone resorption outpaces bone formation

Characterized by massive osteoclastic resorption and extensive bone formation