Talkin' 'Bout (the Circle of) Willis

Let's talk about the back of the head.

The Circle of Willis is a series of arteries connecting critical feeds of blood to the brain. When a connection like this is created in the body--whether it developed that way or was created--it is called an anastomosis. An example of a synthetic anastomosis would be if someone had a section of intestine removed, and the two remaining sections were joined together.

In the Circle of Willis there are smaller arterial sections that would allow certain sections of the brain to be fed at least a little bit by arteries that wouldn't normally be tasked with doing the job, in the event of a failure like a stroke or other trauma. Smaller segments within the Circle of Willis are fed by the internal carotid arteries and the vertebral arteries. The internal carotid arteries are split off from the carotid arteries.

Here's a video. If anatomical terms aren't your thing, just watch as the video highlights where the blood goes.


We always talk in martial arts about protecting your face. Keep your hands up. Protect your jaw. Keep your chin slightly tucked. But all we say about the back of the head is not to let anyone get behind you. We know it's important not to get hit in the back of the head, or in the spine. Perhaps a lot of us would get psyched out if we all knew how catastrophic any blow can be.

Some of the people I support at work have survived a traumatic brain injury. Knowing the science behind their situations may not be at the forefront of my work with them in rehabilitation, but it does help me to be compassionate about what they may be going through, because I know what is damaged and why. I also know more about what can be rehabilitated and what can't. Because I am not a neuroscientist I cannot allow my novice understanding of anatomy to impact the recommendations I make, but it can help me ask better questions of those who are qualified to provide better information, and /that/ can improve my outcomes.

In karate, I use my knowledge of anatomy and physiology--and my knowledge about how my body breaks so many of those rules--to learn, grow, and adapt. When I know how serious a consequence can be, I know to sit out. Knowledge is power, and as Uncle Ben said in "Spider Man," "With great power comes great responsibility."

Last night I made it to karate and I'm glad I did! I did my first successful groundwork. It feels good to have studied anatomy and physiology. It feels incredible to see it in action. Best of all, it feels sublime to watch my lawless body doing what other bodies can do.

There are so many factors involved in success as a martial artist: how my body is built; how bodies are supposed to work; how bodies don't work; how bodies can be improved; how bodies can degenerate; how adaptions can be made; how practices can be improved; and so on, that it makes sense to say that karate is a cradle-to-grave activity.

The body has a lot of little fail-safes like the Circle of Willis. I enjoy learning about those redundancies, and I think it's a worthwhile use of study time because it also reveals the vulnerabilities.

Deep Breathing and Protecting the Airway

Place three fingers right at the tip-top of your sternum, just inside of where your collarbones end. Now, gently turn your head from side to side.  When you feel your fingers move, you've found one of the points where your sterno-cleido-mastoid muscle (SCM) begins! The other is just a little bit farther out to the side, attached to the innermost third of your collarbone.  It's a muscle that helps with rotation of the head, and also lowering the head, among other things.   This tiny muscle is the HULK! Stick with me; knowing anatomy can help your practice, and can rock your sparring like a hurricane.

Every muscle has a point of origin (where it starts) and a point of insertion (where it ends).  The SCM has two points of origin!  It begins at the top of the sternum and the medial third of the clavicle!  Maybe this could be considered one big point, but because it attaches to two places, it makes sense.   The SCM comes together at the back of the neck.  This is usually injured if you experience whiplash.

Why is this beautiful?
Life has created an incredible tool for itself!

The SCM is a muscle that:

• Connects to two different body parts
• The sternum, which holds your ribs together.  That means the SCM is one of many muscles holding your rib cage in place so it doesn't tilt forward.  Imagine what this means for big-chested people: the SCM connects at the back of the neck, the Emerald City gates of all neurological function.  No wonder a breast reduction has serious beneficial implications on pain management.
• Changes direction
• Most major muscles have a "1 or 0" way of working.  The simple bicep either contracts or it doesn't.  The SCM is a muscle that everybody takes seriously.  A little injury can cause a lot of trouble.
  
  
  "And though she be but little, she is fierce."
  

  -William Shakespeare, A Midsummer Night's Dream
  
• Facilitates movement in many directions
• Lateral rotation of the head (side to side)
• Turning to follow the opponent
• Rockin' your very best kata
• Flexion of the head (up and down)
• Bending your head down to protect your airway
• Lifts the rib cage
• The SCM does part of the work of lifting the rib cage up so that you can take a deep breath, the kind that goes to your abdomen and makes you feel really good.
• Sanchin Kata
• Tensho Kata
• Tai Otoshi (body drop)

It's interesting that we have large sheets of muscle on the tops of our skulls because those bones are fused. One would think it would be thick connective tissue, although there is plenty of that, too. From my inexperienced perspective, the explanation may include that the muscles of the skull help facilitate developmental fusion of skull segments in babies, or working connection with the facial and jaw muscles. I've got to be missing something, though.

More info on the SCM:
http://www.innerbody.com/image_musfov/musc38-new.html#full-description

When I was studying medicine I had a place for these ruminations to go. Since I won't likely become well enough to continue my studies, I'm grateful that karate provides an outlet for my thoughts on anatomy and physiology (A&P). Ehlers-Danlos Syndrome (EDS) is a giant anomaly of A&P, but because I live with it at all times it isn't the healthiest place to nest all my curiosities. The lens of having EDS also produces distortions and bias, whereas karate is practiced and studied by a diverse population, and provides for more well-rounded thinking.

This whole post is a little heady (*snicker*) for a Sunday morning, but still fascinating to think about!