The Spinal Cord – Part 1
Part 3: The spinal cord – your body’s information super highway
In our last post we looked at the basic parts of the brain and discovered which functions they govern. Today we will look at the spinal cord. Your brain communicates with the rest of your body via this information super highway and the nerves that branch out from it. Together, the brain and spinal cord form the central nervous system.
The spinal cord
The spinal cord connects your brain to the rest of your body. It is located inside your spine and extends towards your low back as a long, thin bundle of nerve fibres. It is around 40-50cm long, with a diameter of 1-1.5cm. It exits your brain at the base of the skull and extends down to the first vertebrae in your low back (L1-2). Below the level of the first lumbar vertebrae, there are separate fibres called the “terminal strands “(filum terminale) which give longitudinal support to the spinal cord and attach its protective coverings (the meninges) to the tailbone. This final structure is around 20cm long. The spinal cord stops growing in length by about age 4, even though the spinal column continues to lengthen into adulthood. This is why the nerves which supply information to your legs and feet actually originate around the upper lumbar area.
Along your spine, in between each pair of vertebrae, nerves exit the spinal cord and travel out to your arms, legs, and all your organs. The nerves extending out to your arms and legs form the peripheral nervous system.
The spinal cord is very delicate. It is not a solid structure. It has the consistency of a bundle of very thin, cooked spaghetti – extremely delicate, yet very flexible. In our last post we discussed the role of the meninges and discovered how these thin yet strong membranes surround the brain to protect it. The meninges also surround the entire spinal cord. The spinal meninges attach to the rim of the big opening (foramen magnum) at the base of the skull; at the opposite end, they attach to the tailbone. In between, they are fixed to each spinal bone via stretchy ligaments. Their purpose is not only to protect the spinal cord but to hold it in place by suspending it within the spinal canal.
Spinal cord function
The brain continuously sends and receives information about the state of your body and its environment. It does so via sending and receiving messages along the spinal cord. The cord is made up of various different types of nerve fibres: some transmit information about pain; others about the body’s position relative to gravity; yet others inform the brain about soft touch, vibration, temperature, and pressure.
Information travels across the nerve fibres at an incredible speed: signals relating to muscle activity can reach up to 119m/s (390ft/s). Pain travels more slowly, at around 0.6m/s (2ft/s). Imagine you stub your toe: you feel the pressure immediately but it takes another 2-3 seconds before the pain kicks in. This is because pain signals travel more slowly from the injury site to your brain.
Sometimes however, information has to get processed extremely fast. Imagine, for example, that you are running and hit your foot against a stone – you are about to trip over. Your knee jerk reflex kicks in, you kick out your lower leg, and your body is able to steady itself and prevent you from falling over. This kind of information has to get processed extra quickly. The information from your lower extremity travels into your spinal cord and gets processed there directly – it bypasses your brain altogether because having to travel the extra distance would mean an extra fraction of a millisecond. This could make the difference between steadying yourself and face-planting while you are out for a run.
As the spinal cord runs inside your spine, it is important to keep your spine healthy and in optimum shape. If there is a miscommunication between your brain and your body because the spinal cord is not functioning at its optimum level, you may for example feel this as pain, tingling, or numbness in your hands or feet. In our next post we will look at how a misaligned spine may affect the function of the spinal cord. Advanced Biostructural Correction™ keeps your spine properly aligned and moving correctly. This ultimately has an effect on how well your nervous system (and therefore your entire body) functions. In our next post we will explain this connection in more detail.