If you had told me 6 weeks ago that I would spend all my time in my house not leaving it except for a brief few trips for diagnostic trips then another coronary artery intervention in the hospitals near me. Mid September my fragile genes caught up with me to block the left anterior descending coronary artery. I was having a widow maker heart attack early while reading my early morning Saturday Montreal newspaper. No muscular effort precipitated my attack.
We complain about the inefficiencies about our Quebec health care system but within one hour after presenting at St-Mary’s Hospital emergency department I was on the operating table after being sent via ambulance to Montreal’s Jewish General Hospital’s Cath Lab for angioplasty. As can be seen in the images above inside the large coronary vessel labeled LAD I had a similar no-flow event, I was suffering a heart attack. It felt like a big rope had been wrapped around my chest with two people tightening it. I was also in a cold sweat during the acute moments during the start of the attack. My surgeon placed a Drug Eluding Stent inside the LAD artery to keep the vessel from collapsing on itself.
A stent is a delicate device that expands inside the coronary LAD to prevent it from collapsing upon itself. My father had a similar incident that became his last alive moments before he passed away way back in 1969. But at my moment during the myocardial infarct I was having a very real conversation with my father. ” Dad this is what you felt in your burning chest all those long years ago. Now we are united in sharing this moment of destiny.” My father didn’t get a stent to return flow to his heart, his heart muscle never rebounded. During the angioplasty the surgeon discovered 3 more potential blockages. Last Friday at the Royal Victoria Hospital one more stent was positioned. But the best news was that my stunned heart muscle from the first attack was now beating with only a minor motion change within the entire anterior wall. I was now on the road toward recovery.
The time in my house became reflective time.
I pretended I was on my own space mission during my convalescence, limited to roaming only inside my home’s interior, just like the boundaries aboard the International Space Station. But I did read. I did think a lot especially about my work, about what I am trying to accomplish. I did learn the Sir Issac Newton developed many of his insights during a prolonged convalescence in his house, especially his observations on gravity.
So what does a real astronaut think about while aboard the International Space Station ? What might Chris Hadfield thoughts be about gravity, since he is acutely feeling no gravity within his entire body floating about the interior of his house away from home?
Gravity has always been present during the entire saga of evolution. This ultimate orientation has been imprinted into all signaling communication cellular nets since the start of life on Earth. Gravity has always been present until these last few decades of astronauts now living and working in microgravity. So suddenly withdrawing the force of gravity what are some of the physiological changes pertinent to an astronaut might sense within his chest? Listening to my own conversations, my own simple thoughts on a stent now opening up blood flow within my own heart. What happens to normal breathing for an astronaut experiencing anti-gravity effects? Let’s examine some research reports, specifically on the first day of flight aboard the ISS.
The astronauts breathing rate slows down from a pattern within his chest expansion as antigravity begins its separation as if into separate colors behaving like a prism of light separating into the blended spectrum of colors. Breathing in microgravity becomes less of chest expansion involving intercostal muscles with the diaphragm into a more predominate abdominal muscle breathing pattern. So does breathing interact with the gravity sensing vestibular system? In other words if yawning has something to do with perfecting where my body is either horizontal transitioning into vertical what happens to my breathing , anything or nothing? What kind of confirmation is out there in the literature. Surprisingly very little, but I did find some info that starts to get to the heart of the matter.
My convalescence floating in my home for the post heart attack released a flood of thoughts taking extra naps during my days watching the light move around the interior as fall slowly descended into its color shifting outside my space station. So which way does vagal nerve input from lungs influence factors like lung volume interacting with intrapulmonary pressure? On a couple of occasions returning from slumber my mind floated in the sweep of the color spectrum vistas around my space station. Why do we yawn? is a report from the SciRes by William Burke, Vol 5, No. 10, 1572-1579 (2013) http://doi.org/10.4236/health.2013.510213
Burke proposes a biomedical hypothesis, …”that the immediate trigger for a yawn is a restricted collapse of a few alveoli in the lungs.” As the author refutes the common concept that, ….”yawning can be inhibited by deep breathes of air, carbogen or nitrogen,” which refutes the common refrain that, ” a yawn is triggered by either lack of oxygen or by an excess of carbon dioxide.” This leaves according to Burke, the conclusion that, ..” alveollar collapse as the most likely possibility.”
The fractal branching of a tree is similar the internal design of our lungs.
One of the key observations of Burke concerns, …” the fact that alveoli in the basal regions of the lung are more likely to collapse than those in the apical lung region.” The real measure of how our lung functions is called compliance. Lung compliance is the ratio of lung volume difference divided by the pressure difference. Lung compliance is the description of the elastic range of motion between inspiration to expiration. Lung compliance is a elastic/tension change within the shape motion of the lung tissue. Our lungs are tensegrity shape changes dynamically stretching in an elastic range of floating tension changes a la Snelson floating in a dynamic tension/compression balance.
” A lung tightly held by the ribs and the horizontal septum, a lung directly attached to the trunk, specially formed and compactly arranged parabronchi, intertwined atrial muscles, and tightly set air capillaries and blood capillaries form an integrated hierarchy of discrete network system of tension and compression, a tensegrity (tensional integrity) array, which absorbs, transmits, and dissipates stress, stabilizing (strengthening) the lung and its various structural components.” Spectacularly robust! Tensegrity principle explains the mechanical strength of the avian lung. Respir Physiol Neurobiol. 2007 Jan 15;155(1):1-10. Epub 2006 Jun 2. Maina J
Our bodies internally are in a floating suspension net within a gravity field determining the direction of down versus up. The fractal dimension within our lung compliance motion is dynamic tensegrity shape sensing. All the observers in this suspension behave in their dimensional space because gravity is present. But what of antigravity? What happens inside to the astronauts lung compliance where there is no down-up or sideways?
What happens to a lungs tensegrity balance of tension/compression in anti gravity? The system crashes.
According to Burke’s hypothesis, sensing this lung compliance is at the core of one of the reasons for triggering a yawn as a tensegrity shape change within the elements of the lung’s anatomy, seen as a collapse of a few alveoli in the lungs. What Burke terms,…” as a yawning is due to a mild form of atelectasis.” Atelectasis is a term from Greek meaning incomplete extension, defined as the collapse or closure of the lung resulting in reduced or absent gas exchange. It may affect part or all of one lung. It is a condition where the alveoli are deflated. What is very important for the general shape diagram of a tensegrity structure above is the imposed coordinate reference line planes of X-Y-Z, which orients the shape inside a gravity coordinate space. In anti gravity space there is no specific orientation within a X-Y-Z frame work to define the direction of shape sensing within this framework. The shape sensing crashes because the tensegrity forces are different in both direction and strength. The character, the very performance of lung motion elasticity is altered.
Yawning has been medically recommended to prevent the development of atelectasis in those patients experiencing respiratory disorders especially following operations where lung collapsing is a serious complication. Hyperinflation therapy has evolved as a means to prevent or treat atelectasis. Burke is advocating that, ” a very mild form of atelectasis may be a normal feature of regular breathing. ” According to Burke, ” Shallow breathing, in turn, is due to a marked relaxation of the whole body in various states or conditions such as tiredness, boredom, sleepiness, loss of attention, fatigue, hunger, malaise and most surprisingly, observing other people yawning, which is contagious yawning.” In other words in any dramatic state of body tenseness such as paratrooper just about to jump out of an aircraft or a musician about to perform before a large audience, shallow tense breathing (rigid tensegrity shape sensing) reduces lung compliance creating shallow breathing which may lead to mild alveolar collapse, triggering a yawn.
Burke also compared on himself the effects of body position for yawning as he awoke testing the hypothesis that posture effects the degree of alveolar collapse, increasing the chance of alveolar collapse to occur when the body/chest orientation is vertical compared to the body/chest being horizontal, i.e. lying down. ” It is well known when the body is horizontal the lungs experience the same intrapleural pressure at all anatomic regions. But when the chest is oriented in the vertical plane parallel to the Z axis, the gravitational effect increases the intrapleural pressure in the basal regions relative to the apex. ” Yet according to Burke little or no yawns were experienced in the horizontal awaking position compared to an average of 3 yawns in the same measurement time following 15 minutes after awakening when moving around walking with his body/chest parallel to the vertical Z axis. ” It is uncertain what signal might come from the collapsed alveoli to initiate the yawn,” Burke assumed that the signalling is within the vagus nerve with the possibility that the relevant nerves may be those originating from the J-receptors.
Burke speculates with, “Nevertheless in the absence of lung disorders, gravity may provide the simplest explanation for the postural effect toward inducing a shallow effect on alveolar collapse,” as the difference to trigger a yawn. ”
However, recent studies in normal conscious humans demonstrate that going from a deflating state of lung motion to an inflation state is accomplished mainly by the recruitment of alveoli. The number of alveoli increases, while the volume size of the alveoli remains relatively unchanged. If this (elastic shape change of balanced tension/compression a la Snelson) is correct, we can rephrase the ‘alveollar collapse’ as ‘closed alveoli’.’ Burkes final consideration states, ” It is not known how the ‘closed alveoli’ become open but this might be a function of surfactant. If (lung elastic motion) inflation (as a shape change event of elastic tensegrity tension/compression) caused secretion of surfactant at the mouth of a closed alveolus this might cause it to open.”
I might surmise that since the dynamic triggering of recruitment is the likelihood of a grouped alveolar collapse within the basal regions as a gravity based motion elastic reconfiguration the state of alveoli changing from closed to open by inspiration as a yawn induced lung inflation is essentially a tensegrity triggering shape changed yawn. Let me simplify this summation. As an astronaut ventures into antigravity space flight he stops yawning as a consequence, since their is no X-Y-Z tensegrity 3-dimension space, only antigravity space.
So as I wander my home as an imagined space station in my convalesce I contemplate the amazing prospect that a simple yawn is a complex motion triggering within the micro space of our lung acting as a tensegrity trigger to gravity that is so present around me within the space time continuum what I call the yawn GST reflex.