The first visible organ to develop in all vertebrates, that is animals with spines, is the nervous system. It begins as a cluster of cells and an infolding of embryonic tissue forming the neural tube.
Once this structure forms other tissues begin to develop next to the early central nervous system. The somites develop at around 3 weeks, they will later be stimulated by the neural tube to grow into bone, muscle, ligaments and tendons.
Specialised cells clustered along the neural tube, called neural crest cells, migrate into the surrounding tissues, and through stimulation by transcription factors (chemical signals), stimulate the development of all major organs including the musculoskeletal system.
The nervous system is intimately linked to all parts of the body from the very begining of human development.
Click here to see human embryo development.
Click here for a lectures on neural crest cell in embryology
Evolution
Vertebrates evolved some 400-500 million years ago in the sea from a more simple chordate. It seems that we share a common ancient ancestors with the modern sea squirts. The early vertebrates developed into primitive fishes, these then gradually evolved into species that could move onto the land as early amphibians. Over several hundred million years came the reptiles, birds and mammals.
From this evolution, humans are in the lucky position to have developed efficient bodies and large brains.
The function of the spine has remained the same all the way through this vast amount of time. This fact indicates that it is a vital component of vertebrate design.
Click here for video link to lectures on Vertebrate Evolution
At Sunderland Chiropractic Clinic we focus on the fact that the spine serves three vital functions.
Protection
The spines most important function is protection. It physically protects the spinal cord, and via the skull, the brain itself. The spine also protects the haemopoietic bone marrow, or blood cell producing tissue.
Support
The spine provides the structual support for muscles, other organs and the limbs. Its internal position allows the production of great strength whilst also remaining lightweight.
Mobility
The flexibilty in the spine allows for energy efficient movement. Acting like a spring a healthy spine will rebound a lot of the forces it absorbs, a bit like a pogo stick, when we walk.
You are viewing the text version of this site.
To view the full version please install the Adobe Flash Player and ensure your web browser has JavaScript enabled.
Need help? check the requirements page.