🧠 Vagus Nerve: How Your Body Finds Calm or Shuts Down

What Is the Vagus Nerve?

The Vagus Nerve

The vagus nerve is the 10th cranial nerve and one of the most influential nerves in your body. It travels from the brainstem down through the neck, chest, and abdomen, connecting the brain with key organs like the heart, lungs, and digestive system. It’s a master communicator between your body and brain, influencing how you breathe, digest, rest, and even relate to other people.

The vagus nerve connects the brain with all the organs in our body.

Anatomically:

• The vagus nerve (cranial nerve X) arises from the medulla oblongata of the brainstem and descends bilaterally, meaning you have a left and right vagus nerve.

• So anatomically, the vagus nerve runs on both sides of the body — left and right — and passes through the neck, thorax, and abdomen.
  

Functionally (based on Polyvagal Theory):

• The ventral vagal complex is a term from Stephen Porges’ Polyvagal Theory, which divides the vagus into:

  • Ventral vagal pathway – associated with social engagement, calm states, and originates from the nucleus ambiguus.

  • Dorsal vagal pathway – associated with shutdown, immobilisation, and originates from the dorsal motor nucleus.

The ventral vagal fibers innervate structures above the diaphragm, especially in the heart, lungs, larynx, and face, and are bilateral — present on both sides of the body.

Summary:

• The ventral part of the vagus nerve is on both sides of the body.

• It's named "ventral" because of its origin in the ventral brainstem (nucleus ambiguus), not because it's only on the front or a particular side of the body.

• The ventral part of the vagus nerve, also known as the ventral vagal complex, refers more to its functional division than a strict anatomical location.

  
  

Ventral vs. Dorsal Vagus Nerve: So, what's the Difference?

The Ventral Vagus Nerve: Social, Calm, and Engaged

This branch supports social connection, calm breathing, vocalisation, and heart regulation. It's your body's "safe mode."

Signs of a Healthy Ventral Vagus:

• Calm, steady breath

• Social interaction feels natural

• Heart rate is stable
  

The Dorsal Vagus Nerve: Freeze and Shutdown

This older branch controls deep organ regulation and can trigger shutdown during trauma, fear, or overwhelm.

Signs of Dorsal Dominance:

• Emotional numbness or withdrawal

• Digestive sluggishness

• Fatigue or brain fog

  
  

Polyvagal Theory: The Nervous System Ladder

According to Polyvagal Theory by Dr. Stephen Porges, we move between 3 main nervous system states:

1. 🟢 Ventral Vagal (safe)

2. 🟡 Sympathetic (fight/flight)

3. 🔴 Dorsal Vagal (freeze/shutdown)
   

Understanding this helps you track your stress response and support nervous system regulation. Your nervous system is not broken — it’s adaptive. When you understand how your vagus nerve works, you can create a pathway back to safety, calm, and connection.

How to Support a Healthy Vagus Nerve

• 🧘 Slow breathing

• 🎶 Humming, singing, or chanting

• ❄️ Hot/Cold Showers and Cold Ice on your neck to build resilience with exposure to extreme temperatures

• 💬 Safe connection with others

• 🧠 Trauma-informed therapy

  
  

  

  Technique to tone the vagus nerve

Your nervous system is not broken — it’s adaptive. As your brain constantly adapts to our environment based on our experiences, emotions, memories through neuroplasticity, the neurochemical released by the brain directly impact the vagus nerve and our nervous system. Once you understand how your vagus nerve and the nervous system works, you can create a pathway back to safety, calm, and connection.

Human Nervoussystem