SCIENCE OF YIN YOGA 73YIN AND YANG
OF THE NERVOUS SYSTEM
The human nervous system is evolution’s way of creating a method for the
mind to communicate with its 50 trillion cells. Its function is to perceive the
outer world through the senses and then to broadcast that information to
every cell through its integral membrane proteins. This enables all of your
cells to work as a collective community. This harmony among cells, tissues,
and organs increases efficiency and productivity and is a key to survival.
What Is the Autonomic Nervous System?
The human body is designed to seek balance. In science, this is known as
homeostasis. The autonomic nervous system, which regulates the functions
of the body, is one of the many ways that we see homeostasis in action.
I vividly remember eating at a cafe one afternoon when my daughter was
a toddler. Her mom had ordered sushi. On the side of the plate was a small
mound of green stuff. My daughter, who loved avocado, exclaimed, “Yummy.
Guacamole!” Before we could stop her, she had shoveled a huge spoonful
of wasabi into her mouth and swallowed. In about two seconds, her faced
flushed bright red, her eyes rolled demonically into the back of her head,
her mouth flew open, and then she vomited all over the table. Just another
day in the life of parenting a toddler, right? The body is amazing, and when
something isn’t right it knows how to self-correct. Had she not expelled the
wasabi, she could have done serious damage to her G.I. tract.
The system in the body that plays the biggest role in homeostasis and
regulation is the autonomic nervous system. The autonomic nervous system,
sometimes called the subconscious nervous system, is important to main-
taining health. It controls heart activity, blood pressure, breathing, intestinal
activity, temperature regulation, and multiple other functions, all automatically,
without you having to make it happen. It’s easy to take these functions for
granted, but they are definitely something to feel grateful for. I like to look at
this automatic intelligence as another manifestation of the Tao. The autonomic
nervous system consists of two connected parts: the sympathetic nervous
system and the parasympathetic nervous system.
Sympathetic Nervous System
The sympathetic nervous system is responsible for energy production and
the body’s ability to adapt to stress. It is typically more active during the day.
Some of the ways that it interacts with the body is by dilating the pupils,
inhibiting the flow of saliva, accelerating the heartbeat, dilating the lungs,
slowing digestion, producing adrenaline and glucose, and inhibiting bladder
contraction.
The sympathetic nervous system is related to what is commonly known
as fight or flight. Travel back in time and imagine that you are a caveman or