The autonomic nervous system (ANS) is made up of nerves that control the automatic functions throughout the body. It is the master regulator, controlling heart rate, blood pressure, temperature, respiration, sweating, digestion, and other vital functions. These systems operate without you consciously thinking about them because the autonomic nervous system provides the nerve messaging connection between these system organs and the brain. Let’s start thinking about the path these nerves have to take from the heart or digestive system to the brain, where does everything have to pass to get to and from the brain? The neck. Everything goes through the neck.
The autonomic nervous system is made up of two subsystems: the sympathetic autonomic nervous system (SANS) and the parasympathetic autonomic nervous system (PANS). Most organs are directed by both the sympathetic and parasympathetic systems. The sympathetic autonomic nervous system is usually more of a stimulatory system, increasing heart rate and blood pressure when necessary.
Where the parasympathetic autonomic nervous system, generally slows bodily processes, such as reducing heart rate and blood pressure. There are certainly exceptions. Digestion and urination, for instance, are stimulated by the parasympathetic autonomic nervous system and slowed by the sympathetic autonomic nervous system. The sympathetic autonomic nervous system triggers emergency responses or the “fight or flight” responses to prepare for stressful situations and controls the body’s response to stress. The parasympathetic autonomic nervous system conserves energy and restores tissues for ordinary functions, helping to return the body’s equilibrium to the resting state.
(Source: Ross Hauser, MD, Caring Medical Florida)

What does the vagus nerve detect? Increases in inflammation, shifts in stress hormones, even microscopic changes in the diversity of gut microbiota. (…) This makes the vagus nerve the ultimate mind-body connector. (Move The Body, Heal The Mind, 52)

When someone says, “trust your gut!” they are referring to the vagus nerve’s keen ability to sense something is off even (finish typing this when you have a moment)

Social Sensitivity and Brain Activity in Eating Disorders

Individuals with eating disorders display heightened sensitivity to social threats, often rooted in traumatic backgrounds. They are overly attentive to criticism, avoid positive social cues, and frequently misinterpret intentions as hostile. This behaviour aligns with decreased activity in the ventromedial prefrontal cortex, suggesting difficulties in emotional regulation and coping with social stress.

Linking Traits, Cognition, and Brain Activity to Eating Disorders

Eating disorders stem from specific personality traits, cognitive deficits, and distinct brain patterns. Traits like perfectionism and emotional volatility contribute to impulsivity and other eating disorder behaviours, along with avoidance and limited self-control. Cognitive issues, such as difficulties in task-switching or inhibiting responses, play a role with anorexia and bulimia tied to the former, and binge eating to the latter. Brain activity differs across ED types: anorexia is marked by heightened control, bulimia by impulsivity, and binge eating by habitual behaviour and focus challenges.

Surprisingly, it’s likely inflammation. Undoubtedly, you’ve heard of inflammation. It’s what protects the body from infection. Immune cells called cytokines detect an injury or infection and sound an alarm. The alarm summons other immune cells to the site, and their influx cases the inflammation that we recognize as redness and swelling of superficial wounds.
However, all parts of the body can inflame, even the brain. And when the brain inflames, it causes sickness behavior that makes us feel exhausted, antisocial and depressed. Sick at home. Alone in bed. Binge-watching Netflix. Sound familiar? Although no one likes being sick, these behaviors are quite prosocial because they isolate us from others and prevent the spread of infection. It’s the brain’s version of social distancing and a small price to pay for protecting others.

To be clear, stress is not an infectious disease, but it can make you sick.

Cogito, ergo sum. I think, therefore I am. Some people love this quote, but I absolutely hate it. I blame René Descartes, the quote maker, and his theory of min-body dualism for creating the predicament we’re in. “Mind versus body!” he declared. And it’s no secret who we’ve sided with. Just look at how much time we’ve taken away from the body and given to the mind. “With good intention, mind you,” reminds the mind. “After all, mental pursuits are important for productivity.” Yes, but spending all that time in one’s head is actually counterproductive. (…) We need to move to think great. That’s the bottom line.