T4: Histological Organization of Bone

Define osteocyte

mature bone cells; cell that makes up fully formed bones; essentially osteoblasts surrounded by the products they secreted

Define osteoblast

immature, bone-building cells; cells that synthesize bone; primarily active during times of growth and regeneration

Define lacunae

small cavities that contain osteocytes

Define lamellae

concentric rings of hard, calcified matrix; layers of bone

__ is the process of generating new bone

Osteogenesis

__ are found on the inner and outer surfaces of bone

Osteoblasts

Osteoblasts become osteocytes when--

completely surrounded by bony matrix

__ and __ balance their activity to prevent too much/too little bone in healthy individuals

Osteoblasts and osteoclasts

__ __ and __ __ encourages osteoblast activity, offsetting osteoclast activity

More exercise and vitamin D

Define osteoclast

cells that break down bone to use the materials within

What is osteolysis?

acid dissolves bone matrix and releases stored calcium and phosphate

__ are giant, multinucleated cells that balance with osteoblasts

Osteoclasts

__ __ are the stem cells of bone that play a huge role in bone repair and growth

Osteoprogenitor cells

Which bone cell secretes bone matrix?

osteoblasts

What bone cell directs deposition of calcium salts and release of calcium from bone into the bloodstream?

osteocytes

Osteoprogenitor cells are precursors to __ (which become __).

osteoblasts (which become osteocytes)

What is an osteon?

formations characteristic of mature bone and take shape during the process of bone remodeling, or renewal; basic functional unit of compact bone (sometimes referred to a Haversian system)

Define canaliculi

small channel that provides passageways through the hard matrix; interconnect lacunae

What is bone matrix made of?

65% is made of inorganic, calcium phosphatase, and calcium carbonate; 35% is organic, gel, and collagen fibers

The __ __ is the central canal where the blood vessel is, running parallel to the osteon

Haversian canal

What is the Volkmann's canal?

perforating canals that run perpendicular to the bone's long axis, running from one Haversian canal to the next; interconnect osteons