Autonomic Nervous System

Important Part of Digestion

An Illustration of Autonomic Nervous System ( ANS )

Can you imagine using a food processor without wire? Of course not! The wire connects to electricity which is essential to activate the grinding mechanism. I would say ANS is the wiring system* for the "grinder" in our body.

Overview of the Nervous System

The nervous system inside you is divided into two main parts:

1. Central Nervous System - consists of the brain and spinal cord.

2. Peripheral Nervous System - nerves branching out of brain and spinal cord. These nerves are divided into three types:

a. Voluntary Nervous System - cranial nerves and lower spinal nerves.

b. Involuntary Nervous System - also called autonomic nervous system since it regulates body functions which are not under conscious control. For example, you don't have to think about digesting your food as the body takes care of that automatically.

3. Enteric Nervous System. - Some references like Britannica Concise Encyclopedia lists this component. It is embedded in the walls of the stomach and intestines, it controls digestive movement and secretions. Hollistic people call it "the gut's brain."

ANS and Digestion

As food enters the stomach, signals are relayed by the autonomic nervous system between respective digestive organs and the brain to digest, absorb and finally eliminate wastes in the form of feces.

Autonomic nervous system is further divided into two sets of nerves which have opposite effects on the organs they serve, namely:

Sympathetic Nerves - Let's try to locate these nerves. They are between your neck and waist, the lower part of your back plus the nerve cells which lies along side the backbone.

Its main job is to prepare the body for stress. For instance, you wake up late this morning...you dress up in haste to work ...there's only time for few essential things...the sympathetic nerves increases the rate of your heartbeat, increases the flow of blood to muscles and diverts blood away from the gastrointestinal tract thus postponing your urge to defecate.

Hence its other name, " fight or flight system". If you trigger the sympathetic nerves on a regular basis, what are you training your GI to do? To constipate itself...

Parasympathetic Nerves - To locate these nerves, think of the base of your cranium then jummmmp to a large triangular sacrum bone between your two hipbones, it's almost at the end of your tail-like backbone. Look here for the human skeleton diagram. It's from these two ends the parasympathetic nerves spreads out, overlapping with sympathetic nerves in the thorax, abdomen and pelvic region.

Let's continue from the above scenario when you woke up late for work.

At the end of the day, you trudge home amazed how you somehow survive a disastrous morning. Thankfully there's good dinner and after that, sipping a cup of aromatic coffee. Ah, you are ready to use the bathroom, shower and hit the sack.

Here the parasympathetic nerves is playing its main role to "conserve energy, restoring the internal body state to normal by promoting digestion and eliminating urine and feces from the body. In the head [it] increases the production of saliva, while in the stomach and intestines it increases the activity of the smooth muscle and glands." thus promoting peristalsis. Can you see why it is also called "rest and digest system"?

However, in overwhelming situations, like when you have the fright of your life. Parasympathetic nerves stimulates the gut to defecation involuntarily yes...makes you "scared shitless".

Parkinson's, Erectile Dysfunction and Constipation

I used to frown in disapproval to see the latter two showing up together in countless health web pages. But there is a good reason: both are part of the many symptoms of autonomic disorder.

Autonomic nerves regulate smooth muscles in the GI. Parkinson's disease can affect the nervous system, the improper function of the autonomic nervous system as a result causes constipation. A person whose elderly father has Parkinson's disease notes that his father "gets constipated very often and has been in obstruction once [ that ] had to go to the ER, and a few other times, after using a fleet enema, he developed overflow incontinence, having small uncontrolled bowel movements 15-20 times."

Ha! Even cats get constipated when they have autonomic disorder. It's called feline dysautonomia "characterized by constipation, megaesophagus with regurgitation, dilated pupils, protrusion of the nictitating membranes, dry nasal and buccal mucosae, reduced laryngeal secretions and bradycardia." Poor kitties, meowwww!

Being blessed with reasonable measure of health, I hardly notice the existence of the autonomic nervous system, while it transmits vital signals that activate my digestion.

Just as we don't rough handle the wire of food processor, I should take regular meals and sufficient rest, so that I do not cause my ANS to "short-circuit".

* The most basic unit of the nervous system, neurons or nerve cells, are separated by tiny spaces less than one millionth of an inch. These tiny spaces are bridged by chemicals called neurotransmitters. Signals transmitted between two neurons are chemical but within the neurons the signals are electrical. Thus transmission of nerve signals is electrochemical, the frequency of impulses maybe as high as one thousand a second!

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