Nervous System Breakdown

The nervous system is the main communicating and controlling system of the body and it can be subdivided into a few bits for further study. We have to be mindful though as yogis and even as anatomy people that really nothing can be separated. It's almost like if you were to look at a map of the United States, you would see there are all these borders. Some of the borders make sense, it's a mountain range or it's a river. Some of them are land dispute and some of them are just arbitrary.

Given the perspective, if you were to look from the space shuttle down onto the United States, none of those lines actually exist. As we go through all of these little components of the nervous system, we'll just keep in mind that everything is connected. First things first, our nervous system can be subdivided into two major pieces. First piece is the CNS or central nervous system. The central nervous system is really made up of the brain and the spinal cord.

The brain and spinal cord are continuous nervous system material. If I were to hold up a brain, the spinal cord would be attached and it would also be very troubling for everyone in the room. The brain and spinal cord are housed in a bony and fluid and tissue encasement. The brain itself is about somewhere between 86 and 100 billion neurons and it has the consistency of a soft tofu. It really needs to have some protective coverings.

These protective coverings are called the meninges and they're a type of fascia, called visceral fascia. You have a soft inner covering around the brain and spinal cord called the pia mater. Pia meaning soft and mater like our word matter is an energy and matter is mother so it all is born from the mother. The pia mater or soft mother is the soft inner covering of the brain and spinal cord. I always think of it like the silky lingerie around the brain and spinal cord, soft and just delicate.

Moving out concentrically, we have another covering called the arachnoid matter and just like what it sounds like, it looks like a spidery web. If the pia mater was the lingerie, the arachnoid matter would be like a thermal shirt over the silky lingerie. Moving out concentrically, we have the dura mater, the tough mother is what it translates as and this is the down coat over the thermal shirt over the silky lingerie. A well-dressed brain and spinal cord giving it protection and also between the first two layers of those tissues, we have a fluid called the cerebrospinal fluid and this bathes actually made inside the caverns of the brain and it bathes the brain and the spinal cord and carries some interesting messengers with them. Now the spinal cord is continuous but since it has a different job to do as we categorize it in two different categories, the spinal cord runs down those vertebral foramen, down in through the vertebral canal and it terminates its kind of meaty consistency around L2, L3 area.

At that point, it starts to fray like a horse's tail, it's called caudis equino or horse's tail and it looks like a ponytail where it just kind of frays into these finer nerve filaments. Now brain and spinal cord are what is considered in the central nervous system. If it ain't brain and spinal cord and it's in the nervous system, it's in the category of peripheral nervous system or PNS, to be careful how you say that, PNS, enunciate. So if it's not brain and spinal cord in the peripheral nervous system, we can further subdivide it into some bits for study. We have what's called the somatic, sometimes called the voluntary nervous system.

Soma comes from a word meaning body and this is part of the nervous system that we're usually a little bit more familiar with, the voluntary control of our muscles. I could ask you to go get me something and you could leverage movement, contracting the muscles in various different ways, across the joints and bring me what I want, right? Or you cannot, right, it's voluntary. If it's not in the voluntary part of our nervous system, some might use the term involuntary. I don't really like that term too much.

I prefer to call it the autonomic, autonomic. The autonomic, it comes from this root word meaning like autonomy, autonomous. So involuntary to me sounds like, it's involuntary, I have no control, it's involuntary. Not very empowering. Autonomic means there's a law unto itself, right?

It's happening, a law unto itself and it's very much affected by what's going on in the external environment as well as what's going on in your internal environment. So right now you're digesting your last meal and you're not giving it conscious thought, thankfully, right? It's a lot of time wasted if we had to do that. Your heart is beating, you're breathing, glands are secreting, there's a whole symphony of actions going on in your body that are not so much under conscious control but are happening a law unto themselves but if I were to kind of charge towards you, there would be a cascade of changes in your body, right? It would affect you.

Nothing could change in your external environment but you could start kind of thinking in your head like, oh, he says that to me, I'm going to say that to him and I'm, how dare he? You can like work yourself up and have, even though nothing has changed in your external world and reality, inside there's a whole bunch of physiological changes happening. So autonomic can be further subdivided into a few bits and now this is where I think it's really comes into focus for us yogis. Sympathetic can be further subdivided into sympathetic and parasympathetic. Now sympathetic, we might have heard of sympathetic activation as fight or flight.

Those words are a little bit more familiar to most of us. And parasympathetic activation, we might have heard of something called rest and digest. Now this is very much true. That's their claim to fame but I think it's a bit of a misnomer. In the next few episodes, we're going to start to look at some of the beauty of both sympathetic and parasympathetic and how as yogis, we can tap into this autonomic system to bring about changes in our body and our breath and in our lives.

Thank you.