FLUID RESPIRATION: mapping the unseen breath
There are a trillion little breaths happening at the cellular level, let me take you on that journey.
When we hear the word respiration you, like me, can make a quick association with the word breathing, that felt sense of air moving in and out of our nose or mouth, the spread and fall of our ribs, and maybe the soft shifting of our abdomen. All these experiences are familiar to us to one degree or another, but they are only half the story of a breath - the airborne breath, the movement of oxygen into, and carbon-dioxide out of the lungs. The other half of the story is “cellular respiration”, or cellular breathing, also known as internal respiration or secondary respiration. This is the fluid-borne breath, and to follow that part of the story we have to go on a fluid journey.
THE FLUID BREATH
Oxygen from our lungs finds its way into the bloodstream via a delicate exchange within the capillary beds that surround the alveoli: the grape like structures located at the end of the branching of the bronchial tree within in each lung. Capillary beds are the place in which the looping vessels of our blood system change their identity, function and structure, where vessels shape-shift between arteries and veins, (see the images below). This is also the location that marks the beginning of the fluid-borne breath, as well as its terminus.
Through the medium of blood, oxygen makes its way to the heart and from there out into the arterial blood stream where it travels towards the cells of all our tissues: muscle cells, liver cells, skin cells - all the tissue types you can think of. Oxygen molecules do this by hitching a ride on the iron-rich heamoglobin molecules in the red blood cells. They then sail on vast rivers and ever diminishing tributaries until they find small streams wide enough only to allow blood cells in single file to pass through. These tiny vessels, or arterioles, are located in the capillary beds of our tissues and it’s here that the oxygen molecules diffuse into the interstitial fluid surrounding our cells to make the final leg of their journey; finding their way through the cellular membranes into the inner world of the cells themselves.
Meanwhile, there is a reciprocal and simultaneous journey of CO2 molecules departing the cell. They pass through the membrane out into the interstitial fluid of the capillary bed, where they find their way into the blood system via the venules, or tiny veins. Then on they go, lilting through veins and valves, gathering in increasing waves before they wash through the heart and onward again until, at the alveoli, they diffuse into the lung tissue ready to become airborne.



And why do the cells breathe? why do they need this gas exchange? Essentially, when oxygen meets glucose inside a cell several transactions are able to take place that lead to energy being generated in the form of something called ATP (adenosine triphosphate). It’s extremely efficient in that one glucose molecule can give rise to 36-38 molecules of ATP which can be stored and made available whenever energy is needed by our cells. This process is called “aerobic respiration” and its main biproduct is CO2. Energy can also be produced when CO2 meets glucose and this is called “anaerobic respiration”. It’s not so efficient, producing only a couple of molecules of ATP and the main biproduct is lactic acid - you might know the feeling of lactate build-up if you work-out intensely or when you are in training, it can show up in symptoms like muscle fatigue or cramps, and shortness of breath.
TIME FOR A BREATH
Let’s pause. That’s quite a lot of information to get hold of and quite a journey for our imagination to undertake. And, all of this thinking and visualising actually takes cellular energy too.
Take a few mindful breaths. Notice the familiar sensations of the comings and goings, and identify the movements of the ribs and the abdomen.
Stay with airborne breath as you now start to consider that at the very same time each cell in your body is involved in its own breath. Oxygen molecules travelling through the cell membranes to create cellular energy, CO2 molecules passing them by as they move in the opposite direction.
Think about the trillions of cells that together make up your whole body, or maybe move your attention to one location in your body and take your time to acknowledge all the cell types: skin cells, fat cells, bone cells, muscle cells, and more. Each one making its own tiny fluid breath, a cellular inhalation and exhalation as your lungs continue to fill and empty.
Cells, like lots of twinkling stars invisible yet present within in each cycle of the rising and setting sun.
CELLULAR WISDOM
There’s a lot our cells can teach us, particularly in the nature of their semi-permeable membranes, but what can we harvest in terms of somatic wisdom from cellular respiration itself?
We might start by considering how we create our own energy to do what we need to do, and what we have in our reserves for doing the things we like to do. What are our strategies for nourishment be that nutrition, rest, work, relationships, etc? How good are we at supporting ourselves when we need to be resilient? Equally, how good are we at letting go of the things that deplete us?
Life, our cells teach us, is a reciprocal exchange. We are most healthy when we are able to receive and give up with equanimity. We are most healthy when we tend to our inner and outer environment in the knowledge of this reciprocity, when we appreciate the symbiosis of our body and the world.
That’s quite a big thought to end on! Thank you for taking the time to read or listen to this edition of Field Notes. I know how precious your free time is and that there are lot of people clamouring for even a few moments of your attention.
If you happen to be interested in exploring aspects of The Fluid Body, I have a series of three online workshops coming up in the Autumn, drop me a note at info@beverleynolan.com if you’d like details.
Until next time, sending warmest wishes
Beverley
PS And, if you are a paid-subscriber, the Companion Notes are coming soon with thoughts on the breathing of trees and reflections on prana.
You write about these intricate processes in such a clear and digestible way Beverley. Thank you
Thank you, beautiful. I’ll explore that and i am interested in your online workshops in autumn.