Breath - Science and Scriptures (Part 1)

April 10, 2020

Flower lungs

Many of you know that a significant portion of my year 2019 was spent towards my yoga teachers training. I still haven't got the certification but that doesn't stop me from practicing or writing about Yoga. I now see a pattern of obstacles in every formal degree/certificate that I got so far :)

Human intelligence has done all sorts of discoveries in Science to try to understand the esoteric ways of nature. Science is an invention of human intellect and thus called as पौरुषेय (made by humans) whereas Scriptures are अपौरुषेय (not made by humans). I am usually able to relate with philosophy more than I can focus on science. Here I am going to try to combine both. This post is divided into 2 parts. In this part I am writing about some of the subtleties of our breathing mechanism - a significant part of Ashtanga Yoga, and its effect on our physical and mental well being.

Disclaimer: I don't have any institutional education in human anatomy and physiology. My writeup here is based on my understanding, primarily from the book: The Anatomy of Hatha Yoga: A Manual for Students, Teachers, and Practitioners by H. David Coulter. My sister who is also an Anatomy professor helped me review this. Any errors are completely mine. 

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What is the first thing humans do after landing on this earth? They take their first breath! From then on the process of breathing is generally taken for granted until we start to realize the impact of bad breathing habits. Breath is so natural that why would we even want to pay attention to it? On a physical level effective breathing is essential to maintain appropriate levels of oxygen in the body. On a more subtle level, breath directly affects how one thinks and feels, influencing the mental state.

I love how Ramana Maharshi describes it in this shloka from Upadesha Saram:

चित्तवायवश्चित्क्रियायुताः ।

शाखयोर्द्वयी शक्तिमूलका ॥ १२ ॥

Both mind and prana expressed as consciousness and activity respectively are two branches rooted in the same shakti.

In fact, breath is a connection between the body and the mind and thus is so important. It suffers when the body has stress or when the mind is agitated. More on the philosophy in another post.

What and How of Breath?

In the gross form, breath is the air we inhale and exhale. A level below it is the exchange of oxygen and carbon-di-oxide in the cells within the body. At a more subtle level, breath is the manifestation of prana that is responsible for all physiological activity in one's life. Maybe we can stop here and take a breath? :)

The main organ involved in breathing is Lungs in the body. We all studied that in Science as kids right? Lungs are passive spongy air-filled organs in the chest. One important part of the Lungs is the Alveoli - tiny balloon-like air sac endpoints in the respiratory system where the exchange of oxygen and carbon-di-oxide takes place. These get affected in a number of respiratory diseases like Pneumonia, Tuberculosis, ARDS (Acute respiratory distress syndrome - which most COVID-19 patients are at risk for right now), etc. Smoking also causes damage to them. Naturally one can understand why one is unable to breath well in any of these diseases as the body doesn’t receive appropriate amounts of oxygen.

Different Muscles that operate during Breathing

Since the Lungs are passive, breathing takes place due to complex muscular activity. The three main muscles used in the respiration are:

• Diaphragm muscle - umbrella like muscle at the base of the rib cage.
• Intercostal muscles - two types of muscles between the ribs: external and internal intercostals.
• Abdominal muscles - used in many breathing exercises.

Where does all that air go? 

So where does all the air you inhale go? How much do we inhale? Are we using our lungs to full capacity? The main four lung volumes are:

• Tidal volume - the amount of air that moves in and out in one breath. Usually around ½ litre when relaxed.
• Inspiratory Reserve volume - additional air one can inhale after the usual tidal inhalation. ~3 litre.
• Expiratory reserve volume - additional air one can exhale after the normal exhale. Usually around 1 litre.
• Residual volume - amount that remains in the lungs even after exhaling as much as one can exhale. This is usually around 1200 ml.

Lung Volumes Illustrated

How does this correlate to the amount of oxygen we get? Remember, it is only the air that gets to the alveoli that is useful. The amount of air that actually gets to the alveoli is measured by the alveolar ventilation. This is tidal volume minus any air that is left in the nasal passages and other airways in between nostrils and the alveoli, measured per minute.

Our Autonomic nervous system responses

Most of us remain in mainly 2 modes of operations:

• Fight or flight also known as Sympathetic (Stress) nervous system
• Rest and digest also known as Parasympathetic (Peace) nervous system

These are two sides of our autonomic nervous system (ANS) that governs the internal functions of the body - blood pressure, digestion, elimination, glands. Both are important for our proper functioning. ANS is basically maintaining everything that is happening unconsciously within the body.

There is another nervous system - somatic nervous system (SNS) in the body that deals with all things that we do consciously - touch, vision etc. as well as control of skeletal muscles. We might think that breathing is an unconscious act and thus controlled by the ANS but that is not the case. As we discussed before, the act of breathing involves different muscles which are controlled by the SNS. When we sneeze, cough or just take a sigh of relief, our body uses the SNS.

Both SNS and ANS work together for harmony. ANS has a huge effect on our breathing (controlled by SNS function). ANS signals SNS to work differently when needed, for example when the blood isn't getting enough oxygen.

By now we know that our autonomic nervous system (ANS) influences our breathing. Can our breathing influence our ANS? Again ANS is very important in the smooth functioning of our internals and thus our well being. I can't tell my heart to slow down in case of stress but I can use my breath to influence my ANS which can then influence my heart.

"It's like a referral system. The ability to control our breathing consciously gives access to the autonomic functions (e.g. heartbeat, blood pressure, etc.)."

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In the next post, I will talk about how the ancient breathing practices provide benefits and have led many researchers to write their thesis while discovering the workings of these practices.