NATURAL FACULTY: DIGESTIVE TRACT
The Alimentary Canal
Running right down the center or core of the body, from mouth to anus, is a big hollow tube called the digestive tract, or Alimentary Canal. Because most of the substances that are assimilated into, and eliminated from, the body do so via this great tube, it could also be called the Great Central Channel.
For the purposes of anatomical study, we divide the digestive tract into segments, which we call organs, but in reality, all are interconnected, and form one long, seamless tube. At certain points, like the stomach, the tube is wider; at other parts, like the pyloric and ileocecal valves, it's quite narrow. At still other points, like the biliary and pancreatic ducts, other tributary tubes feed various substances into it.
The entire digestive tract and all its organs are afferent attendant vessels of the Natural Faculty. Their main purpose is to digest food and drink into chyle, whose nutrients are then absorbed from the intestines via the veins of the hepatic portal system and sent to the liver, the principal organ of the Natural Faculty, for processing into the Four Humors. The unusable residues, or waste, are then eliminated via the tube's bottom or anal end as feces, or solid waste.
The usual flow of materials through the Alimentary Canal in the digestive process is from top to bottom, or mouth to anus. The food bolus and juices are squeezed and propelled downwards via the rhythmic muscular contraction of peristalsis.
In Greek Medicine, the smooth, coordinated functioning of the digestive tract and its organs is the result of the harmonious cooperation of the Four Administering Virtues, which are specialized derivations of the Natural Force arising in the liver. These four forces, or virtues, in their usual sequence, are: Attractive, Digestive, Retentive, and Expulsive.
When the digestive tract is functioning properly, everything flows smoothly, from top to bottom. Dysfunction arises when things don't flow smoothly, producing obstruction, blockage, or reflux. These give rise to the familiar symptoms of colic, gas, distension, bloating, regurgitation, etc...
Because the entire digestive tract is one seamless, interconnected whole, many close reflex relationships exist between its various organs. Problems or dysfunction arising in one part of the Alimentary Canal will affect or have repercussions on all the others.
The Alimentary Canal is amazingly versatile in that in can both assimilate and eliminate from both its top and bottom ends. Elimination from its top end occurs through vomiting, or emesis. Assimilation from its bottom end can occur through enemas and rectal administration. This makes it very useful and versatile therapeutically. The Alimentary Canal is also the main route of detoxification for the organism.
Phases of Digestion
Holistically speaking, the entire digestive process can be divided into four broad phases, each with its own predominant humor and temperament:
In the upper digestive tract, from the mouth through the esophagus, digestion is primarily Phlegmatic. Food is masticated and mixed with phlegm and saliva to reduce it to a watery, semiliquid state, as all subsequent digestive reactions must occur within an aqueous medium.
In the middle digestive tract, or the stomach and duodenum, digestion is primarily Choleric. Hot, caustic secretions rich in the Choleric digestive virtue, like stomach acids and bile, predominate, and most of the digestion, or nutrient breakdown, occurs here.
Below the duodenum, in the small intestine, digestion is predominantly Sanguine, or moderate and balanced, in temperament. Bicarbonate buffers from the pancreas cool down the excessive heat and acidity from the middle digestive tract and facilitate nutrient absorption, which occurs through the Sanguine Attractive virtue.
In the large intestine, or colon, digestion is predominantly Melancholic in temperament, as the stool is solidified in the descending colon through the drying action of the black bile sent to it from the spleen, and most of the remaining fluids and electrolytes are reabsorbed back into the organism.
The Organs of the Digestive Tract
Let's take a closer look at the organs of the digestive tract, from mouth to anus, and how they work according to the principles of Greek Medicine:
The mouth's basic temperament and function is Phlegmatic, since it mashes and liquefies ingested food and drink, facilitating its expulsion or passage down the digestive tract. The teeth masticate or pulverize the food so its nutrients are more accessible to the digestive enzymes. The tongue manipulates and churns the food mass until it's thoroughly mixed with phlegm and saliva.
The mouth secretes phlegm and saliva. Phlegm reduces the food to a semiliquid state, providing an aqueous medium for nutrient digestion and absorption. Saliva is warm, moist and Sanguine in temperament, and begins the digestion of carbohydrates and the sweet taste, absorbing caloric energy orally and sublingually. This initial caloric absorption exerts an immediate energizing and restorative effect.
The tongue is a mirror of our internal organs, especially the organs of the digestive tract. The tongue's overall condition and appearance reflects that of the digestive organs. The art of interpreting these signs is called tongue diagnosis.
The tongue is also a sense organ, whose sense of taste is essentially Sanguine in character. Of all the tastes, the sweet taste is the most nourishing and Sanguine. Through its sense of taste, the tongue detects the relative concentrations of various nutrients in the food, and signals to the digestive organs which digestive juices and enzymes to secrete. The taste of french fries, for example, will tell the gall bladder to secrtete a lot of bile.
Teeth and Gums
Greek Medicine, as a holistic healing system, sees the health of the teeth and gums as being intimately connected to the health of the rest of the digestive tract, and to that of the organism as a whole. The teeth, as osseous tissue, reflect the overall state of the bones and the soundness of their mineral metabolism.
The health of the teeth and gums, and of the whole oral cavity, is strongly influenced by the biological and metabolic terrain prevailing in the rest of the organism, particularly in the stomach. Chronic imbalances of humor and temperament in the stomach are linked to imbalances of bacterial flora in the mouth that can cause or aggravate tooth decay, gingivitis, or periodontal disease.
Choleric imbalances in the stomach and systemically are linked to red, sore, inflamed bleeding gums. Hyperacidity of the salivary secretions can aggravate tooth decay. If inflammatory and abscess conditions penetrate into the alveolar bone, the teeth can get painful and loose.
Phlegmatic imbalances lead to gums that are too swollen, bloated and lax, enabling food particles to penetrate under them. Melancholic imbalances can aggravate atrophied, receding gums and the formation of excessive bacterial plaque.
Conventional dentistry stresses maintaining local oral cleanliness and hygiene. To this, Greek Medicine adds maintaining a sound mineral metabolism, digestion, stomach function, and an overall balance of the humors and temeraments.
Throat and Esophagus
The functions of the throat and esophagus are to swallow the food bolus and propel it downwards towards the stomach. The pharyngeal cavity in the back of the mouth is the vestibule that forms the common junction of the digestive and respiratory tracts, and is affected by imbalances and pathologies of both systems.
The epiglottis covers the trachea or windpipe and closes it when we swallow, so that the food bolus passes down the esophagus and into the stomach. Once the food or drink passes the epiglottis, its propulsion downwards towards the stomach is done by automatic peristalsis.
The cardiac orifice lies at the bottom of the esophagus at the entry to the stomach. The bottom end of the esophagus also passes through the diaphragm on its way to the stomach.
Hiatal hernia is a condition in which the upper part of the stomach protrudes upwards through the diaphragm, causing frequent regurgitation of the stomach contents into the esophagus. It is commonly associated with Choleric conditions of the stomach like gastritis, hyperacidity and acid reflux, which can erode the mucous lining of the esophagus, as can bulemia, with compulsive vomiting.
Melancholic conditions of the esophagus are mainly the holding of excessive nervous stress and tension in the esophagus. Powerful emotions can also produce a lump in the throat. Constitutionally, some are prone to hold excessive nervous tension in the throat and esophagus, especially those of a Melancholic temperament, or with aggravated melancholy. Globus hystericus is a condition in which excess phlegm, combined with excess melancholy due to nervous stress and tension, combine to produce the sensation (not real) of something stuck in the throat.
Phlegmatic conditions of the esophagus are usually associated with Phlegmatic excesses in the stomach, lungs and respiratory tract. Excess phlegm can congest the throat and esophagus, causing heaviness and oppression. Cold, Phlegmatic excesses in the stomach can cause watery regurgitations into the throat and esophagus.
Like the stomach, the throat and esophagus are frequently affected by psychosomatic stresses, psychological issues, and nervous tension. Chief among these are stuffing and swallowing negative emotions and problems with communication or speaking one's truth. The throat and esophagus are closely connected with the Throat Center, or chakra.
The stomach lies at the center of the digestive tract, and is the first organ to initiate digestion in a big way. The main temperament of the stomach is Hot, Dry and Choleric, and its digestive function is due to hot, caustic stomach acids. These Choleric gastric juices would digest the very stomach itself if it weren't for its protective mucous coaating of the opposite yet complementary Phlegmatic humor.
The thermal aspect of digestion in the stomach is called the Digestive Fire, which has a close relationship with the Metabolic Heat in the liver. This Digestive Fire is inherent in the acidic gastric secretions.
The kinetic aspect of digestion in the stomach is its motility and churning of the food juices in digestion. For its kinetic function, the stomach is the main recipient of the Natural Force in the liver and its Four Administering Virtues. For proper kinetic stomach function, there must be balance and harmony between the stomach and the liver. If the Natural Force in the liver is stagnant and congested, the kinetic functioning of the stomach will often be as well.
Residues of black bile from the neighboring spleen enter the stomach to stimulate and awaken the gastric secretions, and one feels hungry. The Choleric Digestive virtue of the gastric secretions "cooks" or digests the food. When the stomach has thoroughly processed the food, the pyloric valve lets it out in a controlled, regulated fashion. Black bile in the stomach, with its Retentive virtue, constricts the pyloric valve and favors retention of the gastric contents, whereas phlegm in the stomach, with its Expulsive virtue relaxes or dilates the pyloric valve, favoring their expulsion or release. Proper stomach function and the right balance between retention and expulsion depends on the right balance of black bile and phlegm.
Since the stomach is the central organ of the digestive tract and the First Digestion, which happens within the Alimentary Canal, proper digestion depends on proper stomach function. If the stomach doesn't do its job right, then nothing that happens thereafter n the First Digestion will be quite right. The overall strength, vitality and vigor of the First Digestion depends on that of the stomach. To strengthen digestion, we must strengthen the stomach.
If the stomach does not initiate digestion properly, poorly or incompletely digested food will tend to stagnate, ferment and putrefy in the intestines, a condition known as alimentary toxemia. Alimentary toxemia may be caused either by overwhelming the stomach with more food than it can handle, or by an inherent weakness or dyspepsia of the stomach itself.
Choleric conditions of the stomach are chiefly gastritis, hyperacidity, acid reflux and gastric ulcer. These are usually seen in those of a Choleric temperament, but may also be caused by dietary abuses of a Choleric nature.
Phlegmatic conditions of the stomach are chiefly dyspepsia, gastric atony, or a slow, sluggish, weak digestion, as well as stomach hypoacidity. Excess phlegm in the stomach generated by dietary abuses or a cold, weak digestion are often transferred to the lungs via the gastropulminary reflex. Watery regurgitations from the stomach can also occur.
Melancholic conditions of the stomach are chiefly a sour or nervous stomach and gastric colic, gas, distension and bloating. Excesses of melancholy disrupt the stomach function and the smooth, orderly flow of the Natural Force through the stomach. This can lead to stomachaches or a wide variety of gastric reflux disorders, such as burping, belching, hiccups, and eructations or regurgitations.
Sanguine conditions of the stomach are chiefly due to excessive appetite and gastric overload. These include various types of gastrointestinal fermentations and putrefactions.
Reflex Relationships of the Stomach to Other Organs
Being so central and important to the digestive process, the stomach has many important reflex relationships with other organs. These are chiefly as follows:
The lungs are connected to the stomach via the gastropulmonary reflex. By means of this reflex, excess phlegm in the stomach often finds its way into the lungs. By this same gastropulmonary reflex, emesis or therapeutic vomiting can eliminate excess phlegm from the lungs and respiratory tract. If the stomach is overly full, it will impinge on the diaphragm, inhibiting full and deep breathing.
The proper kinetic functioning of the stomach depends on an adequate supply of the Natural Force, which is derived from the Vital Force, and ultimately from the lungs. And so, proper breathing and sufficient fresh air are important for optimum stomach functioning and proper digestion.
The liver's Metabolic Heat, which concocts the humors in the Second Digestion, is the source of the Digestive Fire in the stomach. And so, these two fires are closely connected; as one goes, so usually goes the other.
Similarly, the stomach's kinetic functioning is dependent on the Natural Force from the liver. Imbalances, disharmonies or stagnation of the liver's Natural Force will often create functional disturbances of the stomach.
The liver's receptacle is the gall bladder, which empties into the duodenum. Choleric or nervous, irritable, spasmodic conditions of those organs, being adjacent to the stomach, can also affect it by reflux action.
The intestines are closely related to the stomach, with the latter being the cause and the former being the effect. If the stomach doesn't do its job properly, its problems and dysfunctions are passed on to the intestines in the digestive process.
The colon and the stomach also have a close reflex relationship. Black bile from the spleen is important in regulating the functioning of both organs. While the stomach is the big initiator of the First Digestion, the colon finishes it; and so, in many ways, the functions of these two organs are the reverse of each other. For example, the stomach dumps many fluids and secretions into the GI tract, whereas the colon reabsorbs these fluids back into the organism. If the colon is stagnant, toxic or congested, so often is the stomach, with indigestion and acid reflux common.
The duodenum is only about a foot long, but in all the things it must do, and all the digestive secretions it must receive, at the right time, and in the right amnount, the duodenum is a crucial segment of the digestive tract. The liver and gall bladder secrete yellow bile, which is the vehicle for both absorbing and eliminating fats, into the duodenum. The pancreas must secrete its digestive enzymes and alkaline bicarbonates into the duodenum soon after the stomach's contents exit the pyloric valve; the stomach acids must be buffered and neutralized by the pancreatic juices.
The taste of digestion in the stomach is sharp and sour, due to the strong acids there. When these acids are neutralized by the alkaline pancreatic secretions, salts are created, which give digestion in the duodenum a salty taste. The bile secreted by the liver and gall bladder also contain bile salts. A salty balance between acid and alkaline is a key to the healthy functioning of the duodenum.
The duodenum is vulnerable to Choleric pathologies, since it receives both Choleric stomach acids as well as bile. Most typically, these are duodenal ulcers. If black bile is involved, these ulcers tend to be chronic and indolent.
Because the duodenum is full of moving parts and ducts, which function in a smooth, coordinated manner with their secretions, it's quite vulnerable to nervous, colicky conditions as well. These conditions include biliary dyskinesia, and irritation, inflammation and spasm of the pancreatic and common bile ducts. Colicky, nervous or spasmodic conditions of the duodenum, which are often transferred to it via the organs and ducts that empty into it, can also affect the pyloric valve and stomach by reflux action.
The main function of the small intestine is the absorption of nutrients from the first digestion by the villi. These are sent via the veins of the hepatic portal system to the liver for processing into the Four Humors. By this time, the food juices have been thoroughly mashed, liquefied and digested into a rich, creamy nutrient soup called chyle.
Pepsis, or digestion, continues in the small intestine, alongside the absorption of nutrients, but it isn't as Choleric as it was in the stomach. Because the food juices have been buffered by the alkaline pancreatic juices, the heat of pepsis in the small intestine is milder and more Sanguine in temperament. Sanguine processes of exchange and contact also govern nutrient absorption.
From the villi of the small intestine, nutrients from chyle are absorbed and sent to the liver via the veins of the hepatic portal system. If the veinous blood circulation in the hepatic portal system is stagnant or congested, a condition called portal hypertension, the assimilation of nutrients will be compromised, and intestinal function will be slow and sluggish. If the liver is stagnant or congested with excesses of blood or any other humor, the portal circulation will suffer backup or reflux congestion. Sometimes the portal circulation itself can be stagnant, congested or obstructed. In these cases, excess black bile, which can unduly thicken the blood, is often the culprit. Obstructions of black bile can severely compromise the hepatic portal circulation and impair the overall nutrition of the organism.
The Colon, or Large Intestine
In the colon, the remaining fluids and electrolytes are reabsorbed into the organism by the Retentive Virtue, astringent taste and drying action of black bile. Black bile's drying action also thickens and solidifies the stool, which enables the colon to hold onto it until the time is right for excretion or defecation.
Actually, three different humors, working together in the right harmony and balance, are all essential for normal, healthy defecation and colon function. If any of them is deficient, excessive or otherwise aggravated, colon function will suffer.
Black bile thickens and solidifies the stool, reabsorbs fluids, moisture and electrolytes, and maintains adequate intestinal constriction or tone. If black bile is excessive or aggravated, the stools will be too hard and dry, and difficult to eliminate; there is also likely to be constipation. Aggravations of black bile can also cause gas, bloating, colic and flatulence.
Phlegm and its moisture keeps the stools soft enough to enable them to be expelled through defecation. The colon also has a mucous coat that protects and lubricates it, and facilitates the passage and excretion of the stool. Healthy colon function depends on a proper balance between black bile's dryness and phlegm's wetness. If phlegm is excessive or aggravated, the stools can be excessively soft, loose or watery; copious phlegm may also be present in the stools, or they will be soft, mucilaginous and mucoid. Bowel tone can also be excessively bloated, loose or lax. Supporting the normal Phlegmatic secretions and lubrication of the colon is its share of the Radical Moisture; in older people, whose Radical Moisture is depleted, the colon gets dry, and intestinal lubricants and stool softeners are often needed.
Yellow bile colors the stools brown and acts as a natural laxative, stimulating peristalsis and the defecation reflex. Yellow bile steps into the balance between black bile and phlegm and tips the scales in favor of excretion, or defecation. If yellow bile is excessive or aggravated in the colon, the stools will tend to be soft and loose; they will also tend to be smelly, and may be hot or burning upon defecation. Intestinal transit time tends to be short, as peristalsis is hyperstimulated by the excessive yellow bile.
The colon and its bacterial flora form the backbone of what is called intestinal immunity. Feces are the solid waste product of the Earth element, and growing beneficial intestinal flora, or bacteria, in them is like cultivating a beautiful, sweet-smelling garden, with the harmful, putrefactive bacteria being like stinking, unsightly weeds. By preparing or ripening the stool for elimination, beneficial intestinal flora help maintain colon hygiene and regularity.
Constitutionally speaking, those of a Melancholic temperament generally have the most problems with cultivating beneficial intestinal flora and maintaining intestinal immunity. Otherwise, dietary abuses such as poor or irregular eating habits, poor food selection or combining, insufficient dietary fiber, or overeating and the intestinal congestion, fermentation and putrefaction it causes are usually to blame.
Reflex Relationships of the Colon to Other Organs
In the body, the colon functions somewhat like the roots of a tree and the ground it is planted in. If this terrain is morbid or toxic, toxins will be absorbed through these roots to poison the whole organism. And so, Greek Medicine emphasizes the importance of colon health and hygiene, and recommends periodic cleansing of the colon with enemas and colonics.
The colon is a nervous reflex organ, with reflex relationships to virtually every organ in the body. But since the whole digestive tract is interconnected, and the colon is its end, base or foundation, its closest reflex relationships are with the other digestive organs. If the colon's normal downward flow of peristalsis and defecation isn't functioning properly, and it is congested or constipated, there will be backup, stagnation, or reflux signs and symptoms throughout the digestive tract. These can include esophagitis, acid reflux, sour stomach, abdominal distension and bloating, and much more.
If the colon is morbid and toxic, there can also be toxicity and congestion in the throat, and frequent or recurring sore throats. If the colon is stagnant or constipated, the lung and respiratory function is also often weak, and full inhalation compromised or inhibited.
Anus and Rectum
The anus and rectum constitute the bottom end of the colon, and of the entire digestive tract. Here, at the bottom end of the descending colon, the fecal matter is hardest, densest, and most subject to congestion and impaction. Here also is the greatest risk for polyps, tumors, and abnormal growths.
Here, at the anus, is the Spinal Energy Center that the ancient Greeks called the Hieron osteon, or the sacrum, or sacred bone. It is also known as the Root chakra. It is the seat of the Earth element and its humor, black bile. Chronic excesses and aggravations of black bile in the colon can lead to arthritic disorders in the pelvic and lumbar area.
The most common anal/rectal disorder is hemorrhoids, followed by anal prolapse. Anal prolapse, as well as hemorrhoids, can be caused by chronic constipation and too much straining at the stool.
The hemorrhoidal veins that swell and itch in hemorrhoids are part of the hepatic portal system. And so, conditions like portal hypertension and a congested liver are usually the root cause of hemorrhoids, and dealing with these underlying conditions is necessary if any lasting relief or improvement is to be made.