Thorax:
In the thoracic region of the spine, ribs attach. Each rib has two points of contact with the associated vertebra (these are marked in red, and the rib is cut away where the transverse process is pointed out).

The bellows:
One contact point is on the body of the vertebra. The other rib contact point is on the transverse process. These are flexible and act as an axis for rib elevation and depression - likened to a bucket handle on a bucket - motion for breathing.

In front, the upper ribs attach to the sternum (1-7). Lower ribs attach to the ribs above them (8-10) with a couple of floaters (11 & 12) called floating ribs which have no anterior articulations.

Lumbar Spine...

This is the part of the spine that gets all the press, the part that so often is associated with hurty this or that.

The bodies of the vertebrae here are larger. The ‘small’ of the back, is a common term for the inward curve behind the lumbar spine.

Seen here from the front, it sits on the sacrum which has wing-like extensions (sacral alae) which embrace the pelvis.

The little pointy left over vertebrae at the bottom (coccyx) are to make you be careful on slippery surfaces - or else!

Running through the spinal canal is the spinal cord. Here the outer coverings are opened and held open with black sutures. The cord is thoroughly covered by blood vessels. Tiny nerve rootlets come off like teeth from a comb and collect into bundles as nerve roots which we see coming off at intervals to right & left.

The pars interarticularis, or just plain pars, is the zone (shown in red) where one embryologic formation center meets another. Th e pars can be underdeveloped, even - perhaps - still made of cartilage, or given enough force - broken.

Many microfractures and healing and rehealing can have this area stretched out as fractures allow the upper structures to migrate a bit forward before healing. An elongated pars is sometimes seen.

Over time fractures can form false joints - that is be a place of actual movement.

With backward bending, the upward pointing joint below, jabs right into such a defect - producing speech “ouch”.