Nervous System 101

Jen Meller
Jun 4
5 min read

Updated: Jun 5

Understanding Your Inner Control Center

Welcome to Nervous System 101 — a guide to getting to know the incredible inner system that helps you stay safe, connect with others, and navigate life’s stressors. It’s a science that helps us better understand how we are wired so that we can better serve ourselves and help us heal.

It starts with learning how to listen to your body’s signals.

A man sitting on a couch with his hand over his face

The Nervous System: Your Inner Control Center

Your nervous system is always working in the background — scanning for safety, sending messages to your body, and adjusting how you respond to the world.

It has different “settings” depending on how safe or threatened you feel. Learning to recognize those states is a first step toward finding more regulation and ease.

The Three Guiding Principles of Polyvagal Theory

1. Hierarchy: Your Body’s Built-In Safety Sequence

Your nervous system has a predictable order in how it responds to your environment — and this order is shaped by evolution. Think of it as your body's “safety ladder.”

Here’s how that ladder typically works:

Ventral Vagal State (Safe & Social) The most evolved state. This is where you feel safe, connected, curious, and open. Your heart rate is steady, digestion works well, and you can think clearly and engage with others. It’s the home base we’re always trying to return to.
Sympathetic State (Fight or Flight) If something feels unsafe, your body moves into action mode. You might feel anxious, angry, agitated, or hyper-alert. Blood flows to your muscles. Your heart races. It’s not “bad”—it’s just your body trying to protect you.
Dorsal Vagal State (Shutdown, Numbness, Collapse) When fight or flight doesn’t feel possible — or hasn’t worked — your body flips the switch into conservation mode. You might feel heavy, tired, foggy, detached, or like you’re watching life from underwater. Again, this is a survival response.

This hierarchy isn’t rigid — we can move between these states throughout the day. But understanding the order helps you get curious about where you are and what your body might be needing.

2. Neuroception: The Body's Subconscious Safety Radar

Your nervous system is constantly scanning: “Am I safe right now?”

But it doesn’t do this with logic or language — it does it through neuroception: a subconscious process that uses your senses to detect safety or threat.

Neuroception happens:

Inside your body (a tight chest, relaxed shoulders)
Outside your body (loud noises, someone’s facial expression)
Between bodies (the nervous systems of two people interacting)

What’s important to know is: your body might react to something as unsafe even if your thinking brain knows you're okay. You’re not overreacting. Your nervous system is responding to something, even if you’re not sure what.

The good news? We can learn to listen, then offer signals of safety back to the body.

3. Co-Regulation: Why We Heal in Connection

Humans are wired for connection. In fact, our nervous systems evolved with the assumption that we’d be in community — with someone nearby to help regulate us.

Co-regulation is that warm hug. That steady voice. That presence that says, “You’re not alone.”

And here’s the thing: co-regulation isn’t optional. It’s a biological need. We’re not meant to “just self-regulate” all the time. Babies rely entirely on co-regulation until their nervous systems mature — and even as adults, we still need safe relationships to help us settle and feel seen.

That’s why healing in community, therapy, or loving relationships can be so powerful. When someone else brings their calm, attuned presence to us, our own nervous system has a better chance of returning to center.

Meet Your States of Being

Think of your nervous system like a map of different inner states. Each one brings its own physical sensations, emotional tone, and ways of thinking.

Here are the main regions on the map:

Connected & Steady (Ventral Vagal)

You might feel: Calm, clear, curious. You feel grounded and capable. You can relate to others and to yourself with compassion.

You might notice: Deep breathing, strong connections with others, grounded, healthy thought patterns thoughts

You might need: Supportive routines, creative expression, connection with others, stillness

Activated & Urgent (Sympathetic)

You might feel: Alert, tense, rushed. This is your body’s way of preparing to act. You may feel anxious, angry, or overwhelmed.

You might notice: Racing heart, shallow breath, irritability, spinning thoughts

You might need: Movement, calming breaths, reassurance, slowing down

Shut Down & Numb (Dorsal Vagal)

You might feel: Tired, foggy, distant. When stress feels too big to manage, the system powers down to protect you.

You might notice: Flat affect, heavy limbs, low motivation, hopelessness

You might need: Gentle presence with others, rest, slow reconnection, co-regulation

Sometimes we land squarely in one state. Other times we’re somewhere in between. These blended states are normal — and help us gain a deeper understanding of ourselves.

Noticing What State You're In

Your body gives you clues about where you are on the map. You might feel it in your chest, your breath, your thoughts, or your energy levels.

We’ll practice checking in with a few gentle questions:

What sensations do I notice in my body right now?
What emotions are present?
What thoughts or beliefs are running in the background?
What might my nervous system need?

When the System Feels Stuck

Your nervous system is beautifully designed to shift between states — like changing gears in a car. But stress (especially when it’s chronic or unrelenting) can make the system feel jammed in high alert or stuck in shutdown.

This isn’t your fault — it’s a survival response that’s worked overtime.

Expanding Your Bandwidth

Your “bandwidth” is the range in which your nervous system can stay regulated. When it narrows, even small stressors can feel overwhelming. When it widens, you feel more resilient, more present, and more like yourself.

Building Your Regulation Toolkit

You don’t have to get out of a state to take care of yourself in it. The goal isn’t to fix or force — it’s to gently offer your nervous system cues of safety.

We’ll use:

Body-first tools (Bottom Up) – breath, movement, sound, sensation
Mind-based tools (Top Down) – awareness, reframing, compassion, imagination
Together tools (Co-Regulation) – safe people, pets, nature, music, connection

If you’d like to start practicing at home but aren’t sure where to start, take a look at my <<< Gentle Guide to Nervous System Regulation >>>. In it, I offer regulation practices that you might find helpful as you begin your journey.