How Breath Works (Part 1 of 2) : The Anatomy
I love anatomy, every yoga student of mine knows I love it :) However, I also deeply believe in the more subtle aspects of yoga and the need to disassociate from the outer form and really go within. But the truth is, in the world we live in, yoga classes are primarily physical practices and therefore it becomes the prerogative of every yoga teacher to know and understand human Anatomy. It is my endeavour to share these anatomy snippets with you so you know exactly what you're doing with the your body, until the practice itself becomes a second skin, and you know how to flow in and out of postures in an injury free manner - then you take your journey inwards. There is a lot of debate in the yoga world about what is the right way to breathe. A very well respected authority in the yoga anatomy world, Leslie Kaminoff, has done some amazing work on breath anatomy while busting some myths around breathing in yoga. Before we dive into the myths here are some aspects we need to speak about : What's the difference between Thoracic and Abdominal Cavities
Inhale : The thoracic cavity expands its volume, this pushes downward on the abdominal cavity, which changes shapes as a result of the pressure from above.
Exhale : During quiet breathing, the exhale is the opposite of the above process, the thoracic cavity and lung tissue, spring back to their initial volume, pushing the air out, and returning the abdominal cavity to its pressure shape. A reduction in the elasticity of these tissues will result in a reduction in the body's ability to exhale passively, leading to an increase of muscular breath effort and a host of respiratory problems. What is a diaphragm?
The diaphragm divides the torso into the thoracic and abdominal cavities. It has a deeply domed shape, like a parachute. It gets its shape from the organs that surround it - the heart, the lungs and the liver. Above it the thorax with the lungs and the heart, below is the abdomen.
The image above features the ribs, sternum and costal cartilages in black with the diaphragm in deep red and the heart in bright red. On the left, we see the position of the heart and diaphragm at the peak of inhalation. On the right we see the relaxed diaphragm just finishing the respiration cycle.
The heart, which is attached to the diaphragm via its pericardium (a membranous sac that envelops the heart), moves up and down with the diaphragm.
Also look at the double dome effect of the diaphragm, where the diaphragm is higher on the right side than the left, allowing the liver to be tucked up under the bottom edge of the right ribcage, while the left is lower, allowing more room for the heart.
What other muscles are used to breath? While the Diaphragm is totally capable of moving the abdominal & thoracic cavities on its own, there are "accessory" muscles that helps us sustain the breath process and help us breath in particular ways in yoga asanas (these muscle are : pectoralis minor & major, serratus anterior (my fav!), intercostals muscles & loads of other muscles that help stabilise these big muscles.) Now you know why it is important to keep these muscles active and elastic so that they can make that shape change in the thoracic and abdominal cavities happen for effective breathing.
Watch our for our next post where I'll bust some common myths about breathing!