How Does Breathing Work & Why Does it Use My Core?
By Kate Textores, B.S. P.T.A
Inhale and exhale, inspiration and expiration. No matter how we phrase it in your mind, the process of breathing is far more complicated than we usually give it credit for. Something that seems as basic as, well breathing, is really a connection of parts working together with the lungs at the center point. The act of inhaling and exhaling has to do with muscles, pressure both inside and outside of the lungs, and the brain.
Let’s break this down into some more digestible pieces first. Most of the control for breathing happens in the brain, specifically the brain stem, by being aware of your body’s specific needs for the intake of oxygen (O2) and expulsion of carbon dioxide (CO2) at any given time. Tying this back to last month's topic, if your brain perceives that you are in a fight or flight situation, it knows to increase your rate of breathing (to increase your oxygen intake) and increases your heart rate. This relationship is important to remember because it is the heart that is responsible for pumping blood into the lungs to fill with oxygen that will then be transported by the arteries to the rest of the body. This process is called gas exchange.
Gas exchange is vital for the body to survive. Oxygen is delivered to every part of the body by blood vessels and, once the oxygen is offloaded, these same vessels collect carbon dioxide and return to the lungs to swap these molecules out for more oxygen. This process happens deep within the lungs in the tiny alveoli. Each of these tiny pieces is extremely elastic and is made up of tiny blood vessels called capillaries where oxygen and carbon dioxide are exchanged.
So let's talk about how the air actually gets into the body in the first place. The main muscle of breathing is called your diaphragm and it is a large but thin muscle that spans the bottom of your rib cage and separates your chest cavity from your abdomen. When we inhale, this muscle contracts and moves downward to increase space in the chest cavity so that our very elastic lungs can fill with air. It is sometimes helped (especially during exercises or heavy breathing) by the intercostal muscles that are found between the ribs and the sternocleidomastoid and scalene muscles of the neck. Each of these muscles helps to lift and expand the ribs to create even more space for the lungs to expand. Wanna hear the crazy part? When we exhale, our body just simply relaxes all these muscles which causes the lungs to deflate and expel the CO2 that was just exchanged in the lungs. Crazy right?
There is one last part about breathing that will lead us into how it relates to our core. Surrounding our lungs and heart but between these organs and our rib cage, is a double-walled membrane with space between the two walls called the pleural cavity. This space is pressurized and its pressure is lower than that of the atmosphere. It is the contracting of the diaphragm and other accessory breathing muscles combined with the pressure of the atmosphere that causes air to flow into the lungs. The contraction of the diaphragm downwards along with the accessory muscles also contributes to the increase of intra-abdominal pressure or our core. This increase of pressure in our abdominal cavity also causes a contraction of the pelvic floor muscles to help protect the organs and create core stability! Utilizing this pressure relationship and our breath to maximize core stability is the basis of how we like to teach our patients exercises at A Life in Balance and our patients agree: it can be life-changing!
Resources:
https://www.nhlbi.nih.gov/health-topics/how-lungs-work
https://www.britannica.com/science/human-respiratory-system/Control-of-breathing
