The Science Behind Anxiety - Kristin Moon Science

A few weeks ago when my sons headed back onto college campus, I was feeling a bit out of control. My heart and my thoughts were racing, and I realized I was on my way to having a panic attack. I reached out to my dear friend Michelle O’Dwyer to “talk me down” and she shared some information with me that blew my mind. In fact, what she shared was so interesting that I’ve invited her to share it with you too. It all has to do with the vagus nerve.

I confess that I didn’t know much about the vagus nerve before Michelle clued me in, but now I recognize that it plays a vital role in my well-being. Are you feeling stressed? Anxious? Panicked? If so, this post is for you.

Without further ado, I’ll turn it over to Michelle.

Anxiety

January 1, 2020. It was the beginning of a new decade, and many of us were excited about what a new decade would hold. If you are like me, you love new beginnings and fresh starts, and this seemed like a BIG one. But it wasn’t long before our “new start” began to seem less fresh and exciting and more like a “series of unfortunate events.”

2020 has resembled a train derailment, with one car after another skidding off the rails and leaving disaster around it that we are forced to work around and to help clean up. Some days we wake up not knowing what to be more anxious about – the prospect of a worldwide toilet paper shortage or the arrival of murder hornets. It might be funny if only it weren’t so anxiety-inducing.

Anxiety has clouded much of my life, leaving beautiful moments tinged with shadows that I wish I could wipe away. We all have our crosses to bear, and this is one of mine.

Anxiety can take many forms: panic attacks, insomnia, restlessness, heart arrhythmias, nausea, a feeling of overstimulation or of impending doom. Often the sufferer isn’t really sure what is causing the anxiety – it just is there, and we can’t make it stop.

Did you know that these feelings that we call “anxiety” are the body’s way of trying to keep us alive? There are chemicals in our bodies that create these feelings of anxiety and hypervigilance, and they do serve a purpose besides making us miserable. These feelings are driven by chemicals that are released by our nervous and endocrine systems and they affect every other system in our bodies.

There is a part of our body that almost never gets the recognition it is due for its role in helping our bodies deal with stress and anxiety. It is called the vagus nerve, and knowing how to stimulate this nerve can really help you find calm and peace when you feel anxious.

The Vagus Nerve

The vagus nerve(s) (usually referred to in the singular, though you have a pair of them) are cranial nerves. They are the tenth and the largest of twelve cranial nerves. Sometimes the vagus nerve is called Cranial X, because cranial nerves are often referred to using Roman numerals.

The vagus nerve carries both sensory and motor impulses, and is like a Super Nerve. It branches off of the brainstem and extends through much of the body with various nerves branching off of each side of it. I call it a “Super Nerve” because it innervates and affects SO many organs and systems in the body as a result of the extensive network of nerves and organs that it is connected to. It has a crazy collection of varied things that it affects, including:

the larynx (voicebox)
the pharynx (throat, including our ability to swallow)
the esophagus
taste
the sensation of the skin around the ear
digestion (it has an incredible influence on the speed of our digestion and our general gut health)
the liver
the pancreas and insulin levels
the bladder
the heart rate
our immune system, and specifically our inflammatory responses
respiration and breathing rate
circulation and blood pressure
memory formation

Vasovagal Syncope

Learning about the functions of the vagus nerve is like watching a late-night infomercial – “But wait, there’s more!”

Have you ever been standing too long and suddenly felt dizzy?

Or have you gotten sweaty and felt like you might pass out while undergoing a medical procedure?

Or received unexpected bad news and suddenly had tunnel vision or had to sit down?

These episodes are called “Vasovagal Syncope” and are evidence of your vagus nerve in action.

Essentially, the vagus nerve overreacts in response to a trigger, causing the blood vessels to dilate, blood pressure to drop, and blood to be moved away from the brain. These changes in blood flow can cause fainting, which places the head lower than the heart so that blood is moved back toward the brain, which allows consciousness to be restored.

There is a useful purpose for Vasovagal Syncope – if you are badly injured and experiencing blood loss, your body wants to preserve its blood volume as much as possible. But often this response is triggered unnecessarily, perhaps while watching a movie where a character is losing blood. Our bodies don’t know the difference; they simply respond to a trigger in the form of chemical messages.

Homeostasis

“What is the meaning of life?” is THE huge existential question.

If I asked 10 people, I would probably get 10 different answers, based on the worldview of the person answering. But from a simply biological perspective, the meaning of life is something called “homeostasis.”

Homeostasis is a living thing’s ability to self-regulate its functions and processes to ensure survival. If a living thing fails to maintain homeostasis, it dies. A good way to envision homeostasis is to think of your home’s thermostat. It measures the temperature of your home, and then controls the operation of your furnace to keep your home’s temperature close to the level it is set to maintain. Almost every function of our bodies has some role in helping maintain homeostasis.

When teaching students about homeostasis we often use our body temperature or blood pressure as examples that are easy for them to understand. But there are actually endless examples of ways that our body must maintain a delicate balance of homeostasis from our blood sugar, to our calcium levels, to the microbiome of our intestines. All of this happens all of the time without us ever realizing it.

We see examples of the need for balance and homeostasis in the world, in ecosystems, and all around us. There are margins that our bodies, and our planet, must stay within. So, in my mind, when I think about physiology, I am always thinking of homeostasis. There is always a duality. A yin/yang. In our nervous and endocrine systems, hormones and neurotransmitters work together in pairs that create opposite and competing responses, called “dynamic equilibrium.”

The Sympathetic Nervous System and the Parasympathetic Nervous System

The autonomic nervous system is an important part of our nervous system, and it has two parts: the sympathetic branch and the parasympathetic branch. Both of these systems work together, in opposite ways, to help us survive. It is an incredibly complex system of chemical messages that are sent in response to what we experience around us.

When we feel stressed, the sympathetic division is activated and releases norepinephrine (adrenaline) which activates our “flight or fight” response. Once we feel calm and safe, the parasympathetic division takes over and slows our body down by releasing acetylcholine, which allows us to relax and rest. (This is sometimes called the “rest and digest” response.)

The sympathetic division keeps us alive, but it doesn’t care whether we are being chased by a tiger or just running late for work. It acts the same. We suddenly have a lot of energy generated by our nervous and endocrine systems, but we aren’t running away from something; we are just in our car trying to drive safely to work, or preparing for a test, or trying to cook dinner while our cranky children have meltdowns. Hence… anxiety and panic attacks.

A panic attack is just the sympathetic nervous system going into high gear in response to a stressor. We aren’t running from a tiger, but our heart rate still goes up, our breathing increases, we sweat, and our senses are on high alert, resulting in overstimulation. That’s what anxiety is – living in fight or flight mode when there is nothing to run away from. It really takes a toll, and our bodies can get used to living in that state.

We don’t have all of the answers as to why some people’s bodies are very quick to activate this sympathetic nervous response, but we do have a word for it: “Generalized Anxiety.”

The parasympathetic branch is the answer to extreme anxiety and panic attacks. It slows the heart rate, calms you down, decreases inflammation, increases the rate of digestion, dilates the blood vessels, and allows you to rest. Getting it to activate is the key.

Medications designed to help anxiety affect the chemical messengers that drive these systems by altering the neurotransmitters which lead the stimulation of the vagus nerves. But, in the short term, there are ways to stimulate the vagus nerves to stop the fight/flight mode that we often experience.

Stimulating the Vagus Nerve to Ease Anxiety

A lot of what we know about the brain and nervous system is a result of studying individuals who have had brain or nervous system damage. When neurons (nervous system cells) are changed or damaged, we are able to observe what happens as a result.

Much of what we know about the vagus nerve’s functions is a result of the study of epilepsy. Some years ago, scientists realized that the vagus nerve played a role in seizures. So they began implanting a sort of pacemaker in people with epilepsy that stimulated the vagus nerve in order to prevent seizures. As they did this, they observed changes in patients that went beyond just reducing the number of seizures. They noticed some bad things – a hoarse voice, coughing, trouble swallowing. They also observed that the patients often struggled with a low heart rate and blood pressure. BUT… the patients also had decreased symptoms of depression and anxiety. This knowledge has led to a whole new field of study: learning how the vagus nerve affects depression and anxiety, and how to use this knowledge to help those who suffer from depression, anxiety, PTSD, as well as Alzheimer’s, Parkinson’s, and lots of other diseases.

We know that certain actions and therapies can stimulate the vagus nerve and therefore activate the parasympathetic nervous system. Some of these are things that we normally think of as helpful for dealing with depression and anxiety, but others might seem nonsensical unless we understand that these actions work by stimulating this “Super Nerve” that can stop the “fight/flight” response, slow our bodies down, and bring calm.

Stimulating the vagus nerve can bring short term relief from symptoms of anxiety, but it can also have the long-term benefit of increasing our vagal tone and strengthening our bodies’ parasympathetic responses. Some easy and quick ways to stimulate your vagus nerve include:

being around other people
sunshine
nature
smiling
laughing
deep, slow, diaphragmatic breathing
exercising
praying or meditation
physically stimulating the vagus nerve by humming, singing, clearing your throat, coughing, or gargling
sleeping or laying on your side,
taking a cool shower or splashing cold water on your face
putting an ice pack on your neck

Our bodies are designed to be able to survive incredibly stressful conditions. We aren’t aware of all of the chemical activity that is taking place throughout all of our body systems to help us to endure and recover from stressful experiences. The struggle we have in the modern world is that stressful situations are enduring and ongoing. Our bodies react to stress as if we are in physical danger, and from a biological point of view, we cannot run away from our “predators” when our predators are the clock, our busy schedules, the nightly news, or social media. So we have to do everything we can to try to get our parasympathetic division to do its thing.

When you think about how many organs and systems that the vagus nerve is connected to, and how many functions it affects, it makes so much sense. The parasympathetic division is going to do the opposite of the sympathetic. Both also affect the heart, the pancreas, the liver, blood pressure, breathing rate, heart rate, digestion… so many parts! Continued, chronic stress and anxiety does the body a lot of damage. Working to activate the parasympathetic response is the antidote to the effects of stress and is the key to helping us find peace and calm in place of anxiety.

Michelle O’Dwyer has been an educator for over 20 years. She grew up near Detroit and currently resides in Northern Kentucky. She has been married to her husband Michael for 19 years and she homeschools her two children, Morgan and Mason. Michelle is passionate about studying and teaching Science to students of all ages. She also teaches English to Chinese students through an online platform. In her free time she enjoys playing board games, sewing, reading, and learning new cooking techniques.

What is Homeostasis from Scientific American

The Science of Sweat: A Lesson on Homeostasis

Neuroscience for Kids: The Autonomic Nervous System

5 Reasons to Go For a Walk According to Science

If your high school student is interested in learning more about the human body, check out my full-year high school Anatomy & Physiology class. The class meets one hour a week for a live, interactive class. Students will complete homework assignments, quizzes and tests, and hands-on labs and projects for the remainder of the week. I take care of all of the grading and keep the material engaging and relevant to students. You can learn more about the class, as well as the other online classes I offer here: Live High School Science Classes taught by Dr. Kristin Moon