THE DIGESTIVE (ALIMENTARY) SYSTEM a.k.a - Gastro-intestinal System
The gastro-intestinal system is probably my favorite of all the body systems, which is why I probably treated my former patients with colonic hydrotherapy, liver cleanses, enzymes and detoxification programs. The gastro-intestinal system is fascinating because the process of turning food into something useful takes quite a long journey, and sometimes takes several days to do it.
SALIVA IS (SPITTLE):
Digestion begins in the mouth. From the get-go, once you put food into your mouth and your teeth start ripping at the food, your salivary glands will start squirting a chemical fluid, saliva. Actually, the true medical term for saliva is "spittle" and this is where the term "spit" originates. This fluid is normally tasteless, odorless, clear, viscid and weakly alkaline. It is only neutralized when acted upon by the gastric acid it the stomach. It's composition is made up of water, salts, gases in solution, enzymes, proteins an smalls amounts of urea, uric acid, creatine and amino acids. The function of saliva is to moisten your food, facilitate mastication and swallowing, lubricate the mouth and act as a solvent for waste products, initiate digestion to starches and to assist in regulating water balance. That's quite a job for spit, wouldn't you say? It's fascinating!
Your teeth start grinding away and your tongue starts sloshing around your food back and forth until it forms a bolus. A bolus is really just a big spit-ball of food that is ready to be swallowed. The saliva starts its chemical reactions and magically your food begins to turn to sugar (glucose). Just a couple of more grinds and your tongue pushes the bolus to the back of your throat. Once it arrives in the back of your throat, reflexively the bolus disappears down the throat.
Have you heard anyone say their food went down the wrong pipe? They are probably referring to the epiglottis. The epiglottis is a thin, leaf-shaped structure that is located immediately behind the root of the tongue. Its job is to cover the entrance of the larynx when you swallow, thereby preventing food or liquid from entering the airway (bronchial tubes leading to the lungs).
Next, the muscles of the esophagus start contracting and relaxing. Squeezing the wet ball of food down the esophageal tube. Down, down, down it goes, where it lands, we all know . . the stomach! It's just like squeezing a tube of toothpaste. The cool thing is, you don't have to tell your body to this, it is completely involuntary. This muscular squeezing action is called peristalsis. From the time food enters the esophagus, peristalsis begins. Then, a valve (esophageal sphincter) at the end of the esophagus and at the beginning of the stomach opens automatically and the wet ball lands in your stomach! Note - the esophageal sphincter is also known as the cardiac sphincter because of its location near the apex of the heart.
Your stomach is a pink muscular bag and it really isn't really that big. It is the greed of the human stomach that is big, not its actual size. The actual size is about two fists. The food, which has transformed into sugar (glucose) gets squeezed and pummeled back and forth in a mixture of digestive chemicals.
Acid from the stomach pours from the walls of the stomach and dripping with mucus to keep the walls moist. The stomach is made of muscle and the muscle fibers run horizontally, vertically and diagonally to squeeze and squosh the food-stuff. Again, this is peristalsis, like squeezing a tube of toothpaste. The food is broken down into smaller pieces and then another valve (the pyloric sphincter) and empties the food-stuff into the small intestine.
The small intestine is approximately 23 - 30 feet in length. Once the food-stuff is inside the small intestine, chemicals and other liquids from the kidneys and pancreas break down it down and it mix up even further. The leftovers I guess you could say. The small intestine is lined with tiny finger-like projections called micro-villi. They are similar to sponges where they can absorb large amounts of nutrients from the food you just ate. The micro-villi then carry the nutrients into your bloodstream through the tiny little hole on their tip. This bloodstream full of nutrients will carry its load straight to the liver.
It doesn't take long for your food to hit the bloodstream and wind up in the liver. This means, bad food, alcohol, drugs, etc., will indeed make it to the liver. And as far as we know, the liver has 2,000 functions we know about and 2,000 functions we don't know about. Science doesn't know everything and you'll want to make sure that you aren't tossing your health to chance with what you choose to ingest. The leftovers that your body doesn't use will move on toward the large intestine.
The large intestine is approximately 5 - 8 feet in length. Food enters from the small intestine into the large intestine through the ileo-cecal value (another sphincter). This area is located within inches of your appendix, which is in the lower right quadrant of your abdomen. The large intestine a.k.a. colon is much wider and drier than the small intestine. At the beginning of the large intestine (in the right lower quadrant) it begins with a large sack called the cecum and dangling off the cecum is the appendix, which secretes mucus.
The route of the large intestine makes a large upside down "U." The ascending colon will travel upward (against gravity) in a straight line on the right side of your abdomen until it reaches just under your right ribs. It will then make a 90 degree turn and go straight across your abdomen, just above your naval. This piece of the large intestine is called the transverse colon. The transverse colon will then make a 90 degree turn just underneath the left side of your ribs and head straight down until it reaches the left lower quadrant of your abdomen. There, it will make a sharp turn heading straight to your backside. This small section of the large intestine is called the sigmoid colon. One more angle straight down is called the rectum, which is approximately 6 inches in length.
As the left-overs are gradually pushed through during peristalsis, they become smaller, harder and drier. The reason is because this is where water is extracted from the body and recycled. Once the left-overs have left your body, they are about 1/3 the size of when they first arrived in the small intestines.
Once the food is turned into fecal debris, it will have become varying shades of brown. The last sphincter on this long journey is called the anal sphincter. Any sphincter in the human body must be relaxed in order to open. The anal sphincter is no exception.
JUST THE FACTS:
The gastro-colic reflex should kick in about 20 minutes after you eat, telling you its time to use the restroom and expel the previous meal.
Putting a small stool under your feet while you are on the toilet will help you expel fecal debris much easier and faster.
Normal physiology for bowel movements are at least twice a day. If you go less than this, it may be normal for you, but it is not normal physiology.
Swallowing takes about 10 seconds !
During your Life, your digestive system may devour about 50 tons of food.
It can take food as long as 3 - 4 hours to leave the stomach.
**This web site's goal is to provide you with information that may be useful in attaining optimal health. Nothing in it is meant as a prescription or as medical advice. You should check with your physician before implementing any changes in your exercise or lifestyle habits, especially if you have physical problems or are taking medications of any kind.