Microscopic Anatomy of Compact Bone

Is bone solid

No, it is riddled with small passageways that serve as conduits for nerves and blood vessels

What is the osteon

Aka the Haversian System; the structural unit of bone

Describe an osteon

An elongated cylinder oriented parallel to the long axis of the bone

What is the function of the osteon

weight bearing pillars

What is a lamella

layer of matrix surrounding the central canal of an osteon

What is another name for compact bone

Lamellar bone

How do the lamella help resist torsional stress

The collagen fibers of adjacent lamella run in opposing directions

What runs through the center of each osteon

Central canal/Haversian canal

What is contained in the central canal

Blood vessels and nerves

What are the canals that lie at right angles to the central canal

Perforating canals or Volkmanns Canals

What is the function of the perforating/volkmanns canals

Connect blood vessels and nerve supply of the medullary cavity to the central canals

What lines the perforating canals

endosteum

What are lacunae

where osteocytes live

What are canalculi

The hair-like channels that connect each lacunae, allowing for communication and nutrient transport

How are cannaliculi formed

As bone forms and osteoblasts remain in contact with one another by gap junctions. As the bony matrix calcifies, the canaliculi are formed

What allows for bones to be well nourished

Cannaliculi and gap junctions

What are interstitial lamella

remnants of old osteons; they are between intact osteons

What are circumferential lamella

They are just deep the periosteum and superficial the endosteum; they extend around the circumference of the diaphysis resisting twist of the long bone