. Vertebral Column .

Bismillah, 

as I'm having trouble with remembering this thing again n again

so why not posted it on blog..

Intervertebral disc

* Nucleus polposus - 

 - function(fx) as a ball bearing,

  vertebrae roll over during flexion.extension & 

  lat.bending

 - gives disc elasticity & compressibility

 * Annulus fibrosus

 - fx; coiled spring, holding vertebrae together

medical condition,
As people age, the nucleus pulposus begins to dehydrate, 
which limits its ability to absorb shock. The annulus fibrosus gets 
weaker with age and begins to tear. While this may not cause pain in 
some people, in others one or both of these may cause chronic pain.