quote:
Originally posted by tonightsthenight
Hi personx,
I'd like to hear more on your understanding of the PNS and SNS roles' in respiration.
Bicycle crunches are great. Planks are good too. Just engage the core in everything you do. Even walking is a fantastic exercise in gaining core strength. To truly move (both physically and energetically) from our center of gravity requires tremendous strength of mind and body.
Okay then!
See, the ultimate goal of yoga in my understanding is Sat-Chit-Ananda which means 'Being, Consciousness, Bliss'. This summarizes the final level of purification while the soul is still in the body and everyone simply HAS to agree that this is THE best explanation of that state.
Now, energy wise, there's LOTS and LOTS going on while purification takes place. What I'm trying to explain here is the 'PHYSICAL' part of the purification process.
Firstly, we have to understand that 'meditation' is not something we can 'do'. Its a property, a state you can say that blossoms when we prepare the body for it, meditativeness.
There are only TWO condition which once met, meditation begins on its own : A still body [zero movement; almost; level of movements ~ depth of meditation] and a still mind [zero thoughts].
Now lets take a look at the two autonomous nervous systems in the human body that help the body in different situations by acting accordingly. The one related to being under stress, super excited, giving you a racing heart, shallow breaths, its called the 'Sympathetic Nervous System' [SNS] and the one related with being calm, deep breaths, slow heart rate, euphoria even, that's the 'Para-Sympathetic Nervous System' [PNS].
Stimulating the SNS produces stress supporting neurotransmitters and stuff like cortisol. Stimulating the PNS produces neurotransmitters like endorphins, oxytocin, serotonin, dopamine which help relieve stress and feel blissful.
The doctors and scientists say that these both are supposed to be complementary. Like, when you're in a dangerous situation like being chased by some wild animal in the forest, the SNS is activated which allows you to run fast, think fast, act fast and when that situation is over, the PNS circuitry was 'supposed' to take over switching off the SNS, calming you and making you feel better again.
Now this was how it was 'supposed' to be. [That's what they believe. Not the yogic science.]
Note: The PNS was supposed to be the primary circuitry used by the body and SNS the secondary one i.e. the SNS was supposed to be turned on only in an on-demand basis otherwise the body should be working in PNS mode.
Its well known that the human body works MOST efficiently when its happy, calm i.e working in the PNS mode. [You're working in the PNS mode on days you're happy. That's why time flies on days we're happy and it seems to be too slow on days we're sad.
]
Yogic science is all about cultivating an inner piece within you that NO external stimulus can disturb. [This in the physical sense simply means making the PNS the primary system and working on it to make it the permanent system. This state of being in the PNS mode is precisely what being 'meditative' means.
]
Once we're able to achieve that permanent state of being in the PNS mode, we can summarize that experience as 'Sat-Chit-Ananda'.
Today's lifestyle offers comfort but still people are not 'happy'. This is because in today's lifestyle, there are SO MANY SNS triggers present around us [take traffic for example; anything that promotes stress] that we are constantly using the SNS and not being able to use the PNS properly. This has resulted in SNS becoming the primary system and PNS the secondary.
Almost every other person who tries 'meditating' does it once or twice and leaves it saying 'This doesn't work. It just wasting time.'. Well, everyone who feels so after their first few attempts at 'meditating' is because they are trying to do something that's impossible. [Though even those few tries are helpful for them. Even sitting in meditation for a few minutes everyday is helpful. It helps regain control over the PNS slowly.]
Now, the reason most people can't seem to quiet their mind and sit for meditation at first few tries is because they are trying to do it while they are still in the wrong mode of the nervous system! They feel 'restless' because their SNS is activated, acting as the primary system which does not allow them to sit still and quiet for long.
These sessions of 'meditation' they are having are just the beginning steps towards activating their PNS and once their PNS is activated, meditation occurs. This is where kriyas, mudras and bandhas come into play. The yogis had GREAT knowledge of the human body and they created this system of 'Yoga' of doing things the right way that act as triggers of the PNS. [They had great knowledge because they paid attention to the body. The simplest way to learn everything about anything is to observe. Well, they observed the human body in meditation.
Once you understand something, you can control it.
]
Certain breathing patterns, certain body locks, certain postures ~ all aimed at activating the PNS, slowly making it the primary system.
That's why when you firstly would have tried the body locks, you could only hold them for a few minutes or so. Because the body was still working in SNS mode and you were forcing it to work in the PNS mode. Slowly and gradually as you hold the locks and mudras for longer duration, PNS starts becoming the primary system, hence you're able to hold the locks for much longer duration later. Its a self helping process!
This is why even two minutes of sitting in a simple asana regularly can also be VERY beneficial in the long run.
So, about your question : When the SNS is activated, we breathe irregularly, with gaps in our inhaled air [thus not stimulating the Vagus Nerve endings properly (stimulating them turns on the PNS)] and our heart rate is irregular and fast. Whereas while PNS is activated, we breathe deeply, regularly with no gaps in our inhaled air.
And now I'm realizing I wrote too much outside the scope of your question. Will post it anyway, maybe it will help someone understand what's happening in the body better.
- Px