The Respiratory System!
Arnie Shapiro, M.D.
May – June 2025 • Vol 4, No 16
Inhale. Exhale. Repeat!
Breathing is something we do without having to think about it every minute of our lives. With approximately 12 breaths every minute, we take 18,000 breaths per day. Breathing is the only bodily process that is automatic/autonomic, and yet, it is also amenable to our voluntary control.
Our Respiratory System is another masterpiece of DNA, derived over hundreds of millions of years of evolution. Its function is to get oxygen from the Earth’s atmosphere into our circulatory system, which transports it to all our body’s cells.
As with all higher, land-based animals, we have an oral and/or nasal orifice, an upper airway, a lower airway (trachea, bronchi), and two lungs that have an intimate connection to the circulatory system. More specifically, air enters our nostrils and/or mouth and gets routed through our throat, through our epiglottis (voice box), and into our trachea. The trachea is a tube from our “Adam’s apple” to our mid-chest. There, it divides into two bronchi. The bronchi are the diagonally downward trunks of two massive trees—the lungs—complete with thousands of branches. The ten million or so “leaves” of the two bronchial trees are tiny air sacs called alveoli.
Each alveolus has microscopic capillaries surrounding it, that readily pick up oxygen molecules. These countless oxygen molecules enter countless red blood cells, and get transported to the heart through pulmonary veins. Bright-red, oxygenated blood enters the left chambers of the heart and gets pumped to all organs and cells. The alveoli also collect waste products from the body cells, especially CO2, and these get breathed out.
Our brain (brain stem), has a respiratory center, which monitors blood O2 and CO2 levels, and sets the breathing accordingly to maintain optimal levels.
Another vital part of our respiratory system is the diaphragm. Lying under the lungs, it is a large dome-shaped muscle, attached to the inner ribs. Anatomically, it divides the chest cavity from the abdominal cavity. The contraction of the diaphragm requires stimulation from the phrenic nerve, originating in the respiratory center of the brain stem. The pace and volume of breathing is set in the brain stem.
During inhalation, as the diaphragm contracts, it flattens and lowers. This makes more space in the chest and pushes down on the abdomen. The increased space in the chest draws air in like the opening of an accordion. The corresponding downward push on the abdomen makes the sides and front expand, like pushing down on a beach ball.
When the diaphragm relaxes, it regains its dome shape, air exits the chest, like the closing of an accordion, and the abdominal walls lose expansion. The terms “abdominal breathing” and “diaphragmatic breathing” are one and the same.
Historically, in the past 3000 years, there have been various South-Asian and East-Asian meditative traditions that have used breathing practices to calm the mind in order to find inner peace. One such tradition, Yoga, emphasizes breathing with the qualities of deep, slow, smooth, and rhythmic.
In my experience, breathing with these qualities induces the Relaxation Response, and counters the Stress Response. It also instills a sense of gratitude.
Good foci for “attending our breathing” are the nostrils, the abdomen, and the breath sounds. How can we best take care of our remarkable Respiratory System?
- Engage in regular, aerobic exercise: continuous, moderate, full-body activity, 20–30 minutes per day for 5–7 days per week.
- Maintain a well-balanced diet.
- Maintain good hydration.
- Wear a mask if air quality is poor, stay indoors, and use an air purifier.
- Engage in mindful, meditative, and conscious breathing to calm the mind and develop gratitude for the gifts of the Breath of Life!
In conclusion, our Respiratory System works for us 24/7/365 to supply vital oxygen to help run all our cellular activities. It breathes for us at rest and steps up in activity. It can be an anchor for staying in the present moment. All breaths are Fresh, New, and Now!
— Namaste!
Dr. Shapiro is a career clinic physician who has utilized relaxation techniques with many of his patients. His YouTube channel is: “Arnie Shapiro, MD • Breathing Easy.” Email Dr. Shapiro at: alloydshapiro@gmail.com.