Has a Mind of Its Own

Arnie Shapiro, M.D.
September – October 2026 • Vol 4, No 24

The Vagus Nerve is the 10th Cranial Nerve. It has connections to the Brainstem and to the body’s organs in the oral cavity, neck, chest, and abdomen. It is of crucial importance to well-being. It is a component and organizer of the Parasympathetic Branch of the larger Autonomic Nervous System. The Parasympathetic Nervous System manages energy intake (food, digestion, and storage), governs the immune system, and the conservation of energy, including the Relaxation Response.

The overall function of the Vagus Nerve is Homeostasis—keeping internal conditions in the optimal range for all cells to function properly. It serves this function in all mammals, birds, reptiles, and amphibians.

The Relaxation Response is also known as the “Rest, Digest and Heal” response, which opposes and recovers from the Stress Response. The other branch of the Autonomic Nervous System, the Sympathetic Nervous System, engages the Stress or “Fight or Flight” Response.

In the diagram of the Autonomic Nervous System on the next page, the Vagus Nerve is rep-resented as the pathways connecting the Parasympathetic Nervous System to its target organs. The red pathways (originating mostly in the mid-spinal area) show the connections of the Sympathetic Nervous system and its target organs.

You will note that each organ reacts in opposite ways depending on which side of this system is activated—for instance, the pupils will either dilate or constrict, heart rate will either increase or slow down, digestion will either be restricted or encouraged, and the stress hormones (cortisol, adrenaline, etc.) will either be released into the system or not. Importantly, the immune system, during fight-or-flight, will be turned off as too low of a priority.

There are actually two Vagus Nerves, Left and Right. All branches have both motor and sensory fibers. Both branches include:

• Pharyngeal and laryngeal branches that transmit motor impulses to pharynx and larynx
• Cardiac branches that slow the rate of heartbeat.
• Lung branches that constrict the bronchi.
• Esophageal branches that control involuntary muscles in the esophagus, stomach, gall bladder, pancreas, and small intestine, and can stimulate peristalsis and gastrointestinal secretions

Focusing on blood pressure control, the Vagus Nerve acts in the following way:

The carotid arteries are the first branches of the Aorta, the main artery of the whole body. The first aortic branches are the Carotid Arteries, which direct blood to the head. There is a specialized zone in the Left Carotid Artery called the Carotid Sinus, which detects blood pressure changes. If blood pressure is too high, branches of the Vagus Nerve signal the heart to slow its rhythm, thus lowering blood pressure. This is the “Vasovagal Response.” (Physicians and EMTs can treat Tachycardia with a gentle massage of the Carotid Sinus. It might well slow the heart rate without the use of medications.)

The Vagus Nerve is “De-stress,” as it coordinates the recovery from the Stress Response. The Vagus Nerve choreographs the Relaxation Response. It does so automatic-ally, as soon as a stress response abates, but it can be induced in various ways to activate the Relaxation Response.

I have discussed the Relaxation Response in several prior articles. One of the surest ways to engage the Vagal Relaxation Response is Yogic Breathing, with the qualities of deep, slow, smooth, and rhythmic. Yogic teachings encourage Diaphragmatic Breathing, a.k.a. Abdominal Breathing. Attention is placed on the abdomen, to expand during slow inhalations, and contract during slow exhalations. A similar instruction is found in Zen Meditation.

In addition, regular aerobic exercise is good for cardiovascular fitness and is also practiced for the Vagus Nerve to recover from a “measured stress.” (Not all stress is “bad.”) As we are toning the heart, lungs, and muscles, we are contributing to “Vagal Tone.”

In summary, the Vagus Nerve works 24/7/365 to keep us in balance through activity states and resting states. It has connections to all our vital organs, and maintains homeostasis for all complex animal species.

The Vagus Nerve is Autonomous, which implies “automatic”—it has a mind of its own. It accomplishes internal balance via Nature’s Design. We can feed it, hydrate it, encourage it, and admire it for its versatility and consistency.

Namaste! —Dr. Arnie

Dr. Shapiro is a career clinic physician who has utilized relaxation techniques with many of his patients. Prior articles by Dr. Shapiro can be found on his Columnist page at NaturalLifeNews.com. His YouTube channel is: “Arnie Shapiro, MD • Breathing Easy.” Email Dr. Shapiro at: alloydshapiro@gmail.com.