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Tour of the Organ Body, Part 2: The Stomach

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Photo by Sander Dalhuisen from Unsplash

Published in the Humboldt Independent on October 12, 2021. 

Platypuses and seahorses don’t have one, and if absolutely necessary you could live without one, but mostly it is a good thing to have a stomach, that repository of food responsible for preparing what has been ingested for the absorption of nutrients to follow.

How does the stomach work?

…everyone’s stomach is about the same size…

From svelte supermodels to heavyweight Sumo wrestlers, everyone’s stomach is about the same size, 12 inches long and 6 inches wide, roughly shaped like a bota bag, and sitting to the left of the liver, tucked under the left side of your ribcage.

After chewing and swallowing, food travels down a tube called the esophagus, linking your mouth with the stomach via the esophageal sphincter at its base, whereupon it is deposited into the upper chamber of the stomach. That structure contracts to push the food into the larger lower chambers. There, a cocktail of digestive enzymes and hydrochloric acid breaks everything down so that nutrients can be absorbed. From the stomach, the broken down food passes into the small intestine where much of the nutrient upload occurs. At this point food has been transformed into chyme and the stomach’s work is done for now. Depending on the types of food taken in, as well as the volume, that transformation takes about 4-8 hours.

Just beneath the outer wall of the stomach is a ropy, lumpy wall of smooth muscles called rugae. These coiled folds of muscle contract and relax in order to churn the food around, like an internal vita-mix. They also can expand the stomach from a resting capacity of about 2.5 fluid ounces to that of about a quart (32 ounces) of contents.

The next layer internal to the rugae is a thick coating of mucus which protects the stomach wall from the highly acidic gastric juices which are almost as corrosive as battery acid. Cells within the mucosal structure secrete the ingredients of the acidic juices that break food down. The stomach responds to hormonal and neural triggers by making it capable of secreting these gastric juices at certain times, such as when you have just pulled into the parking lot of your favorite restaurant.

Mmm, food.

The stomach’s main job is to break things down, but some absorption of substances does occur.

Different foods break down at different rates, with fats taking the longest, and sugary foods moving through rapidly.

The stomach’s main job is to break things down, but some absorption of substances does occur. Water is absorbed quickly and vitamin B12 is one of few nutrients absorbed via the stomach. Uptake of alcohol and some drugs happens rapidly as well.

The stomach also produces hormones that are secreted directly into the bloodstream and are responsible not only for stimulating the appetite but also in support of the liver, gallbladder, and pancreas.

In our language, to “stomach” something, or “have the stomach for” this or that means to tolerate or be able to endure some kind of trial, so it makes sense that this organ is well understood as managing the transformation of a foreign substance into an integrated one. As such, the stomach is also the internal body’s first line of defense, sterilizing everything we eat and wiping out many potentially harmful bacteria and toxins.

What could go wrong?

…treat your cauldron of transformation with kindness and care…

What could go wrong, you may ask, in this well-defended vat of highly corrosive juices that could dissolve your teeth even faster than coca cola could? Well, if you are one of the 18-27 percent of North Americans suffering from GERD (gastroesophageal reflux disease) you already know. The most prevalent stomach issue in our culture, GERD results when the stomach contents or gastric juices make their way back up into the esophagus, causing heartburn, chest pain, and possibly damaging the esophagus if left unchecked.

Lifestyle changes such as diet adjustments, eating less, staying away from late night binging and excessive alcohol, supplemented by the use of occasional over-the-counter meds can bring many cases of GERD under control, but see your provider if you are experiencing symptoms that interfere with your quality of life.

The stomach is innervated by the vagus nerve, that special 10th cranial nerve that carries information directly from the brain to many vital organs. When the vagus nerve is healthy and functioning well, the parasympathetic nervous system, which allows the body to relax into rest and digest mode, is active and food can be readily digested. However, when the sympathetic nervous system is stimulated and the vagus nerve suppressed, the body goes into fight or flight mode and digestion slows down.

In milder cases of digestive slow-down, relaxation techniques of all kinds have had good results restoring vagal tone and easing stomach distress. In extreme situations, a condition known as gastroparesis can result, requiring a nutritional overhaul or medical intervention.

Gastric ulcers occur when the lining of the stomach erodes and can no longer protect the stomach walls from acid damage, causing pain and bleeding. Treatments vary depending on severity of the damage. Many ulcers heal with the use of drugs limiting the production of acid. Others are caused by an infection, which must be eradicated completely. Severe ulcers may require surgery.

The acid levels in the stomach can be too high or too low causing various symptoms of digestive upset and can be treated to bring the pH into balance.

Many stomach ailments are the result of other health issues in the body so treatments often depend on what those primary causes are.

If you experience changes in your digestion, regular bouts of heartburn or chest pain after eating, bloating, nausea, diarrhea, etc. with no recognizable cause, see your provider as a work-up of your stomach may possibly reveal a condition with a simple remedy.

Having the stomach for the situation our world currently finds itself in is no easy ask. So make sure to treat your cauldron of transformation with kindness and care so that you can continue to digest everything that comes your way. Otherwise you may come back as a platypus or a seahorse.

Submitted on behalf of the SoHum Health Outreach Department

Ann Constantino, submitted on behalf of the SoHum Health’s Outreach department.