Spinal Cord and The Sense of Touch: What's the Connection?

Human beings have Touch receptors located in varying densities over our bodies. In the hand, touch receptors are most densely located in our fingertips, which is why our fingers are more sensitive to touch than our palms. There are two pathways that touch takes to the brain. The spinalthalamic pathway is the slower of the two pathways, however, it is the route from the spinal cord to the brain which carries most of the information regarding skin temperature and pain. That is why when we become ill and have a fever, it is not necessarily detected right away. Or if we burn ourselves on the stove, the pain might increase a day or so after the initial incident. The pain takes time to travel.

On the other hand, the dorsal-column-medial-lemniscal (DCML) pathway is the route from the spinal cord to the brain which carries signals from skin, muscles, tendons and joints. This is due to wider-diameter axons and fewer synapses which, therefore conveys messages and information more quickly to the brain. For example, my right knee gives me a lot of pain on a fairly consistent basis. When I hear my right knee crack or pop, I know that I will feel a significant amount of pain shortly after. Since the pain is in the joints or tendons of my knee, I feel it quickly. The spinal cord is the most important piece of the nervous system. It can be life-changing to have spinal cord damage, especially the higher up the injury is. For instance, Superman Christopher Reeve suffered fractures to the top two vertebrae, which is considered the most serious of cervical injuries, which also damaged his spinal cord. He could not move anything below his neck, and he was barely able to turn his head if at all. He was unable to feel any part of his body below his neck and was hooked up to a respirator for the 10 years following his injury ultimately resulting in his passing. The lesson here is to be very careful when dealing with a spinal cord injury. If there is a chance for you to lose feeling below the waste, the activity is probably not worth the time.

Ross