Everyone on the planet experiences stress and relaxation. Some experience one more than the other. Stress can come suddenly at an inconvenient time and many struggle to control it. Over the next three articles, we will learn what controls our reaction to situations, how to control that reaction, and why athletes, specialists, doctors, and everyday people should be using it. So, to start off, I want to introduce the Autonomic Nervous System, the very thing that controls how you react to stuff happening. Therefore, what is the Autonomic Nervous System?

The Autonomic Nervous System is the branch of your peripheral nervous system that regulates the functions of the internal organs, like your heart and stomach, and also controls cardiac muscles. The effects of Autonomic Nervous System over your muscles and organs are not consistent. The system takes signals that you are picking up from your surrounding environment and then makes fine tune adjustments to your body. This could be body temperature, controlling heart rate, and sending additional blood to a particular area. The effects of the system change depending on the situation you are in and which part of the autonomic system is in control at that moment.

The Autonomic Nervous System is controlled by two opposing forces that control the same organs but have the opposite effects. These systems are known as the Sympathetic Nervous System, this excites the body and prepares it for activity, while the other is called the Parasympathetic Nervous System, which does the opposite. These combating nervous systems are how we feel different emotions and feelings, such as stress, fear, courage, whatever.

The Sympathetic Nervous System makes us think of the term sympathy, so the idea of calm and understanding comes to mind. However, calm is not a part of this nervous system’s dictionary. The Sympathetic Nervous System is the what causes the “fight, flight, or freeze” response. The Parasympathetic Nervous System does the opposite, it allows the body to be calm, digest, and relax. Both systems use the same mechanisms to operate, but have slightly different structures and originate from different parts of the body.

The Sympathetic Nervous System originates from the Thoracolumbar Area, which is between the thoracic and lumbar vertebrae. Researchers saw the network of nerves radiating from the middle of the spine coordinates the functions of many organs at once and it was given its name from the Greek word for “feeling together”. In contrast to that, the nerves for your Parasympathetic Nervous System begin both above and below. They’re Craniosacral, meaning they originate from the base of the brain and from the sacral spinal cord. Since these nerves are the frame of the starting points of the Sympathetic Nervous System, they earned the name Parasympathetic meaning “besides the sympathetic”. Both of parts of the Autonomic Nervous System require two neurons to operate and these neurons meet in ganglia, the clusters of neuron cell bodies.

Each system has ganglia that are located in different locations. The Sympathetic Ganglia are located around the spinal cord, with the specific purpose to send out quick signals to the entire body just in case of any “fight or flight” situations. The Parasympathetic Ganglia are located near or inside specific organs, away from the spinal cord. These ganglia are activated only in specific situations where the action is required, such as digesting food inside the stomach.

The connections, or axons, between the different nervous systems, are different lengths. The Sympathetic Nervous Systems axons are shorter, making it easier for the small stressors to activate the different effectors in the system. This is why a small stressful event can have such an effect on us; all of the effectors are activated quickly. In contrast, the Parasympathetic Nervous System axons are longer, taking more time for communication to each of the organs. This nervous system communication on a need basis, communicating with specific organs when they are needed, such as digesting food.

This is the Autonomic Nervous System, including the two major parts of that system. Stay tuned for an article next week to understand how to control this system in times of stress, such as competitions or test taking. Tag or share with a friend if this is something they are interested in!