The Anatomy and Structure of Your Back

Messages travel in the opposite direction. If you happen to touch a hot utensil with your foot, pain signals travel up the nerves of the foot and then into the spinal cord, which carries them on up to the brain. Only when they arrive at the brain, are you consciously aware of the pain.

So the spinal cord is basically the great communications channel of the body. If it is damaged, which happens only at the time of a fairly severe injury, and then there will be serious trouble. But happily, hardly any of the various disorders causing back pain produce damage to the spinal cord.

You must have, perhaps, realized that the spinal cord is a vitally important organ like the brain. You might suppose that the ideal way to shield the spinal cord would be with a straight, one-piece bony tube, much as the skull protects the brain. But such a spine would neither allow motion nor possess the necessary protective, energy-absorbing properties.

The Structure

Thus, the backbone, as the name would suggest, is not a single bone but a column or a long vertical chain of small bony units called vertebrae, which are separated from one another by firm and resilient shock-absorbers called intervertebral discs and held in place by strong muscles, ligaments and bony processes. It is as though in a column, the constituent bricks were separated from one another by rubber pads instead of mortar and laced together by strong elastic thongs allowing the brick column to wave, as it were, in the breeze.

The movement between any two vertebrae is quite small. But since there are a large number of vertebrae, considerable movement, indeed, is possible at the spine.

The Purpose of Backbone

A visit to the natural history section of a museum will show you the various varieties of spines in different animals, birds, reptiles and fishes ranging from the giant dinosaurs and whales to the smallest of birds and fishes. The pattern of the backbone is similar in all species and it serves the same purposes.

* To house and protect the spinal cord, the vital cable linking the brain to all other parts of the body

* To bear the arms through the shoulder girdle, the legs through the pelvic girdle, the skull and the ribs

* To provide broad, bony areas for the attachment of muscles, ligaments and tendons that permit the body's movement.

Our spine is a compromise between two opposite necessities : that of stability and that of mobility.

The Requirements

The tall column of bone must be cohesive enough to maintain its essential shape, even while bearing a heavy weight. It must also withstand both vertical and horizontal stresses. If the various vertebrae were hinged together as loosely as our elbows or knees so that each pair of vertebrae could flop back and forth over a 90 degree angle, we would, perhaps, not be able even to rise to a sitting posture. We would certainly be unable to stand up and walk.

The requirement of stability could be met by making the spine a single rigid piece of bone. But that would either make most of our familiar movements impossible or would grossly curtail them. Flexibility is the second necessity.

The Conclusion

Happily, our spine, through its peculiar structure, efficiently integrates these two opposing properties of stability and mobility. That makes it one of the most fascinating and elegant of all mechanical structures in the animal kingdom, indeed, a marvel of biological engineering.

More info on SPINE HERE.

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