Chapter 6 - The Skeletal System: Bone Tissue

Describe the cellular composition of bone tissue and the functions of each type of cell.

- Osteoprogenitor Cells: unspecialized bone stem cells derived from mesenchyme, the tissue from which almost all connective tissues are formed. They are the only bone cells to undergo cell division; the resulting cells develop into osteoblasts. Found along in inner periosteum, endosteum, and in the canals within the bone that have blood vessels. - Osteoblasts: bone-building cells that synthesize and secrete collagen fibers and other organic components, secrete matrix material needed to build the extracellular matrix of bone tissue, and they initiate calcification. - Osteocytes: mature, main bone cells in the bone tissue, They maintain daily metabolism, such as the exchange of nutrients and wastes with the blood. - Osteoclasts: bone-breaking (cell resorption) cells. They regulate blood calcium level, releases powerful lysosomal enzymes and acids that digest protein and mineral components of the underlying extracellular bone matrix.

Compare the structural and functional differences between compact and spongy bone tissue.

Compact BT: this is the strongest form of bone tissue that contains osteons (haversian systems) with little space between them. They lie over spongy bone tissue in the epiphysis and makes up most of the diaphysis bone tissue Sponge BT: does not contain osteons, but instead consists of trabeculae that surrounds redbone, marrow-filled spaces. This tissue forms most of the structure of short, flat, and irregular bones, as well as the epiphysis interior in long bones. Also makes bones lighter for easier improvement. Both of these BT allows for protection, support, and stress resistance

Explain why bone tissue is classified as a connective tissue.

Like other connective tissues, bone (osseous tissue) contains an abundant extracellular matrix that surrounds separated cells.

_______ contributes to the hardness of the bone while ______ gives it flexibility.

Mineral salts' collagen and other organics

Describe how exercise and mechanical stress affect bone tissue.

When placed under stress, bone tissue becomes stronger through increased deposition of mineral salts and production of collagen fibers by osteoblasts. Without mechanical stress, bone does not remodel normally because bone resorption occurs more quickly than bone formation.