Most of your vital bodily systems and their responses are regulated by the autonomic nervous system (ANS) which operates below your conscious awareness. That’s why you don’t have to think about breathing, digestion, or heartbeat. Your brain and body just automatically manage the processes. (Thank goodness!)
The ANS has three branches: the sympathetic nervous system (SNS); the parasympathetic nervous system (PNS); and the enteric nervous system. The PNS, sometimes referred to as the “rest and digest” system, calms your body. The SNS is the “fight or flight” system and is your body’s first responder, getting it ready to run or fight for your life in an emergency. The enteric nervous system regulates your gastrointestinal tract.
The PNS and SNS evolved hand in hand to keep you alive. You need them both. If your SNS were surgically disconnected, you’d live. However, if your PNS were disconnected, you couldn’t survive. The PNS is vital to your mental and physical health and there are many ways you can activate it to benefit you.
Here’s what you need to know.
How Does the Parasympathetic Nervous System Help You?
The PNS puts your body at ease so you can process not only your food but also your emotions. The SNS is your body’s stress response and puts it on alert when it feels your safety and survival are threatened. Just like you can’t drive a car by stomping on the gas and the brake at the same time, it’s best when the SNS, the gas pedal, and the PNS, the brakes, work together in coordination.
Ideally, you want to exist predominantly in a baseline parasympathetic arousal state of calm peacefulness with mild, infrequent SNS activation for enthusiasm, vitality, wholesome passions, and occasional spikes to deal with demanding situations. These days, a lot of us live stress-filled lives where our SNS is activating too frequently or is always “on.” Too much stress and long-term activation of the SNS harms your physical brain and its functioning. Chronic stress makes you forgetful and emotional and increases your susceptibility to anxiety, depression, Alzheimer’s, many mental illnesses, and physical health conditions
The PNS relaxes and reduces your body’s functions, putting it in a state where it feels calm enough to “rest and digest.” It slows down your heart rate, conserves energy, reduces inflammation, and controls muscle contraction. It also manages many important bodily systems, including digestion, respiration, reproduction, hormone production, cardiovascular regulation, and relaxation. The PNS plays an important role in overall health and well-being because it counterbalances the SNS stress response. Specifically, the PNS controls:
The PNS is closely linked to the respiratory system and helps you regulate the volume and speed of each breath. Breathing is an unusual bodily function in that it’s both involuntary and voluntary. Other vital systems, like digestion or circulation, happen without conscious influence from you. You couldn’t control them if you tried.
Breathing is also managed subconsciously — most of the time. But at any moment, you can take control and change how you breathe which simultaneously alters your emotions and nervous system. Therefore, controlling your breathing is a sure and quick way to consciously choose which nervous system — the PNS or SNS — is activated. Controlled, deep breathing brings more oxygen into your body, slows your heart rate, and engages your PNS instantly.