Page 81 - ASOP ROT Study Guide

15 . 2 The Intervertebral Disc
These are cylindrical discs between the vertebrae. They are very prone to disease and so it is
important to understand a little about their structure and function. It is also important to realise that
they do not really function in isolation but that the whole system of bones, ligaments, muscles and
discs works together in maintaining the structure and mechanical function of the spine.

http://www.pioneerhealthcare.co.uk/services/neurosurgery/back-
conditions/intervertebral-disc-prolapse

Structure
The disc is made of two layers: the inner nucleus pulposus and the outer annulus fibrosis.
Function
The function of a disc is to absorb shock and prevent jarring of the axial skeleton. It can also distort
in any direction and so, together with the synovial facet joints, allows movement of the vertebral
column whilst maintaining overall stability during load bearing.

16. SPINAL STABILITY

There is no need to know about the muscles and ligaments of the spine in detail. The most
important aspect of these structures is their contribution to the stability the spine.
If we draw a picture of the spine and include the curves as discussed earlier, we are aware that the"
curves are balanced (see Figure 46A). However when we hang the ribs, chest contents and
abdomen on the spine there is a natural tendency for the whole structure to fall forwards (see