From October through mid December, weekly blog posts will relate physiology, the science of the human body, to yoga. Videos go up on Monday; and the blog post will follow on Tuesday. This month’s focus will be the immune system.
What do the Endangered Species Act, Roe. v. Wade, and the Natural Killer Cell have in common?
The Endangered Species Act was passed; Roe v. Wade ruled that a right to privacy extended to a woman’s right to have an abortion; and the Natural Killer Cell was discovered and named by scientist Rolf Kiessling all in the year 1973. Okay, what does this have to do with yoga? I wanted to think of a clever way to introduce this month’s focus; In the Mood to Learn: Your Immune System and Yoga. I also wanted to loosely demonstrate how every mind takes information and organizes it, and in the organization process, information is always left out.
Acknowledging that information is left out is good when diving into the ocean of science.
Here the organizing thread is 1973.
The Natural Killer Cell is part of the immune system, which I will write about today.
The thread that holds the immune system together is this; the system’s job is to protect your body from pathogens, small microorganisms that either cause disease or cause damage. Oh, and a lesser thought of function*: to prevent the body from getting fluid build up in the interstitial fluid, called edema. Also, to really understand edema you must understand the lungs and the kidney and the skin because all three can pave the way; and one must also understand how the muscular system moves the lymph in the lymphatic vessels, and then how the nervous system communicates to the muscular system to move the lymph.
Now, that, I would call holistic medicine.
Are you a little overwhelmed?
Stay with me, okay. This is new. I always think it’s better to be a little lost and a little challenged than the alternative.
When a yoga teacher says, “Practice shoulderstand and it will drain your lymphatic system, what does this mean?” And furthermore, do you really need to do a classical shoulderstand to get the benefits?
I’m going to say: no, you do not need to do a classical shoulderstand to receive the greatest benefits from the pose. You can do a simpler, more accessible variation and get very similar benefits without the risks to your cervical spine.
And here is the science behind why I think what I think.
Shoulderstand is an awesome pose for some bodies; if you are lucky enough to have x-rays of your own spine and can see that you have a strong lordotic cervical curve; the discs between the cervical vertebrae are not worn out; and the flexors and extensors in your neck are equally strong, shoulderstand is, well, awesome.
This is where I introduce you to the basic structure of the lymphatic system in order to show you why I think viparita karani is an excellent alternative to “drain the lymphatic system” as many yoga teachers say. This pose can be done with the legs simply up a wall; or with a block underneath the sacrum and the thigh bones dropping down into the sockets as the legs engage.
First of all, the lymphatic system is basically fluid moving through vessels that supports and relies on a dominant, closed system called the circulatory system which is also fluid moving through vessels. Other examples of fluid are blood, mucosa, sweat and semen. The circulatory system is made up of red blood cells, proteins, water, and smaller components; and the lymphatic system is made up of white blood cells, protein, water, and other components.
The immune system can be used interchangeably with the lymphatic system but to make it clear; the lymphatic system is always the immune system but the immune system may include broader components.
Blood is everywhere; you can grow more blood vessels through exercise and the body can create more blood cells through erythropoeisis; which makes it easier for oxygen to get to your cells and for healthy cellular responses to occur. Most of the networks of blood vessels throughout your body have parallel (or almost parallel) tracts of lymphatic vessels. The lymphatic system’s responsibility is to drain extra fluid from the blood so it doesn’t build up between the walls of the blood vessels and the walls of the lymphatic vessels, causing edema**; and to protect the body from pathogens.
The lymphatic system relies on the high pressure gradient created by blood being pumped from the heart to function. Meaning, like the shy co-dependent keyboardist in the corner, the lymphatic system would be lost if there wasn’t a strong drummer setting the beat.
And yet what does it mean when someone says, “Oh, yes, put your feet above your head and it will drain your lymphatic system.” And why does it matter?
The lymphatic system is a network that from its outer appearance looks much like the circulatory system. A system has walls and and requires permission or chemicals or pressure to allow something new in or something out. The walls of the lymphatic system are friendlier than those of the circulatory system, which means it is easier for proteins to get into the lymphatic system than to get back into the circulatory system. Furthermore, the lymphatic system is the home of cells like the Natural Killer Cell so named in 1973.
Natural Killers Cells grow to adulthood in lymphatic tissues; but they can find their way into the blood vessels. I may touch on this in a later post. NKC’s attack both microbes and tumor cells.
To review, the lymphatic system is a co-dependent low pressure support system. It is responsible for killing invaders (pathogens), and for maintaining a pressure gradient that prevents fluid build up.
When a person puts their feet above their hips in viparita karani, the valves within the veins and the lymphatic vessels that return blood to the heart and the subclavian vein via the thoracic duct do not have to work as hard. The main duct that drains lymph from the neck and the head and the lower limbs is located starting at L2 (yes, that’s the lumbar) and is called the thoracic duct.
This is where I show you a specific picture.
Please look for the cisterna chyli, that is the beginning of the thoracic duct. If you can see that big green spleen, the cysterna chyli is below it and to the left.
I’m going to argue that the gentle pressure gradient created by viparita karani is as good if not better than the gradient created by stacking the entire body above the head as in salamba sarvangasana.
This is where you may have questions. If you do, please do send them to me. If you’d like to get more like this to supplement the videos, please subscribe to my weekly newsletter. I will do my best to connect the missing dots for you with the feedback. If you feel overwhelmed, that might be because learning physiology is a little like learning a new language. So into the abyss, we go!
*The study of the function of the human body is Physiology; in Anatomy, we learn that form directly relates to function. For example, your stomach consists of large folds called rugae which serves two functions, 1. it creates more surface area for absorption, and 2. It allows the stomach to stretch.