Ready, Signal, Fire: Nerve Supply
Every activity your body performs is based on the activity of your nervous system. Whether it’s the rhythmic contractions of your heart and digestive system, or the rhythm of your golf swing, the activity of your nervous system determines how your body works. Your sensitive nervous system integrates the activity of every cell, tissue, and organ system in your body.
The language of the nervous system is the signals that are sent through the nerve fibers: the nerve impulse. In many ways, nerves act like bundles of wires that carry signals to convey information. As each of the nerve fibers in the bundle sends out an impulse, or fires, a signal is transmitted so that your body always acts in harmony. As nerve impulses reach their destination, the signals are like on/off switches that regulate and integrate every activity in your body.
The activation of nerve impulses strengthens and develops the pathways along which the impulses travel. In other words, repeating a phone number, or the movement of a free throw, strengthens the neural pathway so that it will be more powerful in the future. In this way, nerve fibers create new pathways and reinforce existing ones to create the ability to learn, move, feel, and think.
The nerve supply to your brain is critical
Millions of bits of information are collected from every part of your body and then travel through your spinal cord to your brain. This nerve supply input to your brain is essential for your brain to function. So much so that the highest sensory input to the brain, the fifth cranial nerve, is the dividing line of brain activity. If a lesion above this point prevented sensory information from reaching the brain, it would shut down. If the same lesion were to occur in the brain below this point, the brain remains active.
In other words, while we know that the brain is a supercomputer that runs the body, it is equally true that the body’s nerve supply is what runs the brain. Your brain runs your body, but your body feeds your brain. And according to Dr. John Medina, director of the Seattle Pacific University Brain Center, the most important fuel is movement. Movement, he says in his 2008 book Brain Rules, “acts directly on the molecular machinery of the brain itself. It increases the creation, survival, and resistance of neurons to damage and stress.”
Movement, Nervous System and Your Sixth Sense: Proprioception
Your sixth sense is an essential function of your nervous system called proprioception. It’s how you know where to place your feet when you walk, how a batter can throw a bat into the path of an incoming ball, and how you can lock both fingers behind your head without looking. Proprioception is your body’s ability to be aware of where you are in space.
Surprisingly, the vast majority of the information that travels through your nervous system is below the surface. Furman and Gallo, in their textbook The neurophysics of human behavior, report that throughout the nervous system there are trillions of bits of information that flow through the nerves. Of these, we are aware of around fifty in any one time period. The constant evaluation of movement information through the proprioceptive part of your nervous system is equally behind the scenes. However, it has a powerful influence on your health.
The authors of this program, wellness chiropractors, have seen firsthand how proper function of the nervous system and proprioception is an essential element of health through working with patients, as chiropractors have seen for over 100 years. . Roger Sperry, PhD, received the Nobel Prize in Medicine in 1981 for his work in brain research. This is how he described the importance of the impact of proprioception and its contribution to the essential element of innervation for general health. “More than 90 percent of the brain’s energy output is used to engage with the physical body in its gravitational field. The more mechanically distorted a person is, the less energy available to think, metabolize, and heal.”
The unconscious understanding of body positions and movements has always been the critical element of all moving animal species. Without it, it is impossible to carry out the basic functions of finding food and water, shelter and procreation. Because of this, the proprioception component of your nerve supply is programmed to regulate your body’s ability to handle stress.
Stress and your nervous system
Ultimately, it is your nervous system that is responsible for managing stress. Stress comes from three categories of sources: chemical, physical, and mental. That is, stress is the result of unhealthy choices in fuel, air, and spark. However, once your body encounters stress, there is a common response from your body.
The physiologist Hans Selye was the first to coin the term stress a little over fifty years ago. The hallmark of the stress response within your body (the stress response) is the release of stress hormones. As explained below, the nervous system controls the release of these hormones. When your body perceives something as stress (read: your nervous system detects a stressor), it sends signals to release hormones. These signals are controlled by a part of the nervous system called the sympathetic nervous system. Adrenaline and noradrenaline, also known as epinephrine and norepinephrine, along with cortisol are the initiators of a system-wide stress response in your body.
Fight or Flight, Rest and Repair, and Your Nervous System
Just as being awake and being asleep are two separate and distinct states, being stressed and being in a state of healing and repair are two separate and distinct states. When our body is in a state of stress, stress symptoms are experienced through hormonal release stimulated by the nervous system, preparing the body for a state of activity. This means tearing down tissue, getting ready to burn energy, and getting ready to move. Blood is sent to the muscles, away from the organs, blood pressure rises as the vessels constrict, digestion slows and immune responses weaken as the body prepares for action. This feeling of stress, often referred to as the fight or flight response or fight or flight stress, is directed by the sympathetic nervous system.
The sympathetic nervous system is used by your body in response to stress, or in other words, anything your body perceives as a threat. Acting intelligently, your body’s response to threats is to prepare for action: fight or flight. Even thinking about a stressful event will cause you to experience the influence of the sympathetic nervous system on your body.
To do this, however, there is a cost. Expending energy to deal with a threat means stopping rest and repair activities. Sympathetic nervous system activity has an opposite system in your body dedicated to rest and repair called the parasympathetic nervous system.
Your parasympathetic nervous system is responsible for digestion, relaxation, and reproductive activity. This is the system that your body activates during times of safety for healing, tissue repair, and procreation. In order to heal and repair effectively, you must be in a state of rest and repair.
Research over the past twenty-five years has shown the extent of your nervous system’s influence on the function of two other “supersystems” within your body: your immune system and your endocrine or hormonal system.
The hard-wired connection between your hormones, your immune system, and your nervous system
Before about twenty-five years ago, conventional science did not understand the intimate connection between the immune and nervous systems. However, chiropractors’ patients reaped the benefits of improved nervous system function for decades before this. Check out this example of life-saving results from patients of chiropractors, physicians trained to remove interference with nervous system function, experienced during the 1918 flu pandemic.
In fact, every immune organ in your body is highly influenced by your nervous system communication. The immune organs located in your body, including your network of lymph nodes, your thymus, spleen, and bone marrow, and also most importantly your digestive system, have their activity directed by your nervous system.
This connection is also one of the underlying mechanisms that explains why you are more susceptible to getting sick when stressed. During a period of stress, it switches to a more sympathetic fight or flight mode, which promotes the release of stress hormones. The chronic release of the stress hormone makes you more prone to experiencing stress symptoms and more susceptible to disease.
Today, the research showing how the immune system, the hormonal system, and the nervous system are interconnected continues to grow. To read more, check out these links on this growing field of psychoneuroimmunology.
