Video summary
When the body encounters stress, the HPA axis is activated and the vagus nerve immediately signals all organs to prepare for a fight-or-flight response. This physiological shift causes the heart rate to increase, breathing to quicken, and salivation to change, while even minor acute stressors can cause incremental changes in the gut microbiome. In the intestines specifically, digestion halts as peristalsis speeds up to push waste out of the system, which explains why anxiety often triggers symptoms like irritable bowel syndrome, flatulence, or diarrhea. Essentially, the vagus nerve orchestrates this rapid transition from a rest-and-digest state to a high-alert survival mode throughout the body.
The vagus nerve also receives crucial sensory input through its connection with the trigeminal nerve, which innervates the face and communicates emotional states directly to the brain. Facial expressions act as biological signals; for instance, raising eyebrows in curiosity or smiling triggers positive pathways that suggest safety, while scowling or frowning activates threat detection mechanisms. Additionally, the auricular branches of the vagus nerve located on the outer ear, inside the ear canal, and on the tragus can be stimulated through massage or TENS units to help activate the rest-and-digest function. These various points of entry allow the nervous system to constantly interpret environmental cues and internal feelings to determine whether a situation is safe or dangerous.
Trauma plays a significant role in how the vagus nerve responds to these signals by creating learned shortcuts, or schemas, that label specific smells, sights, or places as threats based on past negative experiences. When sensory organs detect a trigger associated with trauma, the information travels up the vagus nerve to the brain's default mode network, which operates on autopilot and instantly initiates a stress response without conscious evaluation. This automatic reaction bypasses higher-order thinking, causing the body to react as if it is in immediate danger even when there is no actual physical threat present in the current moment.
To manage these automatic reactions, it is essential to recalibrate the vagus nerve by learning to deactivate the autopilot network and activate the executive control network responsible for higher-order thinking. This process involves consciously asking oneself whether one is actually safe in the present moment, rather than reacting based on outdated trauma responses from the past. By recognizing that a situation which once caused harm no longer poses a threat, individuals can interrupt the default stress cycle and restore balance to their nervous system. Ultimately, understanding these mechanisms allows for better regulation of the body's response to stress and helps in breaking the cycle of chronic anxiety triggered by traumatic memories.
Read the full video transcript
What happens when you get stressed? When
that HPA axis gets kicked off, the vagus
nerve tells all of those organs, "Hey,
threat, warning, fight or flee." So,
what happens? The heart rate increases.
Uh we may start salivating more.
We start breathing of more quickly most
of the time.
Um and our
gut microbiome changes, especially if
the stress is ongoing. There's an
ongoing change, but there are
incremental or or minute changes even
with a
uh
acute stressor.
And then down in our intestines, we see
the vagus nerve
communicating that there's a threat. So,
what happens in your intestines?
Everything speeds up. It's not time to
rest and digest. It's time to fight or
flee. So, we're going to push that stuff
out, which when people get anxious, they
tend to have more IBS, more um irritable
bowel, more um flatulence, more diarrhea
to you know, I don't want to get too
graphic for you.
But all of this or a lot of this is
controlled by the vagus nerve.
So, we do want to recognize that when
our vagus nerve is not behaving
helpfully,
then it can trigger
a variety of symptoms throughout our
body.
Now, I said earlier we're going to talk
about the trigeminal nerve. The
trigeminal nerve connects to the vagus
nerve, and the trigeminal nerve
innervates our face.
Um
in uh
certain theories, they talk about your
third eye up here, and your ophthalmic
zone nerve really comes up right between
your eyes, and that communicates to your
vagus nerve. So, if you raise your
eyebrows like you're curious about
something, that communicates to your
vagus nerve, "Hey, that's a curious
look." If you scowl,
um that communicates to your vagus
nerve, "Mhm, there might [clears throat]
be a threat going on."
When you smile, your maxillary zone, uh
areas of the trigeminal nerve, are are
triggered. And that tells the vagus
nerve, "Hey, this person is smiling, so
there must be something positive going
on." And likewise, when you activate
those frown muscles,
um
it communicates again to the vagus
nerve,
"What's going on? The person is making
certain movements and stimulating the
vagus nerve by virtue of the set of
muscles that it's innervating."
And finally, the auricular branches of
the vagus nerve. And auricular means
ear.
And there's a lot of information on
auricular stimulation of the vagus nerve
using TENS units, which again, we're
going to talk about in part three. But,
I do want you to recognize, and I have a
video on vagus nerve massage, that your
vagus nerve, um and you can see in the
picture probably better than you can see
me just pointing to my ear. But, on the
outer side of your ear, there's a couple
of points. So, massaging there, kind of
under where your um ear rolls, if you
want to call it, um
massaging there, and then inside in the
concave area of your ear, there are also
other points. And then on what's called
the tragus, which is the little flap of
skin that covers your ear hole,
for lack of a better word, um that is
also innervated.
So, all through your ear, there are
nerves that are activated,
um,
parts of the vagus nerve that are
activated. So, when we stimulate those,
we theoretically are activating the rest
and digest
part of the vagus nerve.
So, ultimately, what's important to know
about the vagus nerve is that it runs
throughout your body taking in sensory
information and sending it to the brain
to find out what to do. How does this
relate to trauma?
Well, when you experience trauma, the
brain learns from that and creates what
we've called called in other videos
schema or shortcuts about when this
situation occurs, it's
a threat.
Therefore, when the body receives
information, when the sensory organs
pick up information or triggers for that
trauma, the vagus nerve sends that
information up to the brain and the
brain says, "Uh-oh, I know what this
means. In the past, when we've
encountered this smell or this sight or
this place,
it's meant really bad mojo.
So, I'm going to trigger the stress
response.
All of this takes place in what we call
our default mode network or our
autopilot network. And one of the
tricks, and I know I'm getting ahead of
myself, one of the tricks that is
important or tools, I guess, that's
important for recalibrating
the
vagus nerve and the orienting reflex is
to
help the person
learn how to deactivate that autopilot
and activate what they call the
executive control network or basically
our higher order thinking, our ability
to say, "Okay, in the past this really
sucked. In the present, am I safe?