Exam 2 Review:  Chapter 6:  Bone Histology

bone = osseous tissue - The dense, semirigid, porous, vascular innervated calcified connective tissue forming the major portion of the skeleton; it consists of a dense organic matrix of proteins and glycoproteins and an inorganic, mineral component containing primarily calcium phosphate salts (hydroxyapatite).

compact bone tissue - The hard, dense bone composed of osteons that forms the surface layer of all mature bones and the shafts of long bones.

spongy bone tissue - The less dense strutwork of bars and plates (trabeculae) of bone which fills much or all of the interior of mature bones which provides additional strength with a minimum of extra mass; the spaces in between are occupied by red or yellow marrow.  [aka cancellous bone]

osteoblasts - The stem cells from which bone tissue develops; bone-forming cells; located in the periosteum and endosteum of bones; these cells play an active role in bone remodeling and repair and in blood calcium and phosphate ion homeostasis.

osteocytes - The mature cytoplasmically-branched bone cells embedded within lacunae in the matrix of mineralized bone tissue; these cells play an active role in blood calcium and phosphate ion homeostasis.

osteoclasts - The specialized bone cells which have the capacity to enzymatically dissolve bone tissue; located in the periosteum and endosteum of bones; these cells play an active role in bone remodeling and repair and in blood calcium and phosphate ion homeostasis.

lacuna - A cavity, space, or depression, within the mineralized matrix of bone or cartilage and containing bone or cells cartilage respectively.

hydroxyapatite - The principal calcium phosphate salt (mineral) of bone matrix, Ca₅(PO₄)₃OH, which provides the compressional strength of vertebrate bone and tooth dentine.

calcification = mineralization - The hardening of cartilage, bone and tooth tissue by impregnation with calcium phosphate salts; also the pathological deposition of calcium phosphate salts in soft tissues or secretions of the body, e.g., in connective tissues or in the bile or urine drainage systems.

trabeculae - Any of the supporting strands of connective tissue projecting into an organ and constituting part of the framework of that organ, e.g., lymph nodes, spleen.  Any of the fine spicules, struts, bars and plates forming a network in spongy = cancellous bone which provide sufficient load-bearing support despite a minimum of mass.

List:

1.  the two basic kinds of bone tissue.

          compact and spongy = cancellous

2.  the important bone cell types involved in bone homeostasis (i.e. formation, remodeling, healing, etc.) and their specific functions.

5.  the basic components of connective tissue found in bone.

          water,
          mineralized matrix (proteoglycans, proteins, especially collagen, calcium phosphate salts, especially hydroxyapatite, and other salts),
          stem cells (osteoblasts), a direct blood supply, a direct nerve supply

Sketch and Label

3. a cross section of a typical osteon or Haversian system.

 
4. the histology of compact bone.

5. the histology of hyaline cartilage.