Intervertebral discs are the 23 narrow spongy shock absorbers 
which
fit between the 24 separate bones of you spine. Without the discs
these bones would grate and crunch every time you moved.
Each disc has a strong fibrous outer casing - called the annulus
fibrosus - and a soft, squashy, jelly-like interior called the nucleus
pulposus - which is reinforced with strands of fibre.
Intervertebral
discs have very little in the way of nerve supply and contain no
blood. They are made up largely of water. As you get older the amount
of fluid in your discs will diminish slightly - and as a result
you will get shorter.
Other information can be found at:
Bulging Disc
Herniated Disc
Prolapsed Disc
