Although you can hear, see and feel the process of digestion, we are just beginning to understand it’s vital role in our overall health.
Digestion influences our:
- Skin, including rashes, itches, acne and eczema
- Mental health including depression, anxiety, autism and dementia
- Joint health including arthritis and other joint pain
- Immunity including auto immune diseases
And I’d bet anything not on this list, is also related to our digestive health!
Generally we think of digestion starting in the mouth.
In my opinion, digestion starts in our brain.
Think about the last time you had a really good meal.
Whether it’s a piping hot Sunday evening roast complete with veggies and gravy or a fish taco full of smooth and creamy guacamole with just the right spices or perhaps a chocolate truffle you feltl melting in your mouth, the mere thought of food can release saliva!
The production of saliva needs a trigger and seeing, smelling and thinking about food can be a trigger.
Saliva contains enzymes to start chemical digestion while chewing mechanically breaks down our food into smaller pieces prior to swallowing.
Saliva comes from four locations – two under our tongue where the fold of skin connects to our tongue while the other two are located on the inside of each cheek.
If you’re curious, the sublingual papillae under our tongue provide a constant supply of saliva.
The parotid papillae inside our cheeks secrete saliva for immediate need, especially when eating.
Saliva contains calcium, hormones and other immune system products, and is often used to test for these substances originating in our blood 
Salivary glands release enzymes also starting the digestion process.
- Parotid glands release amylase for carbohydrate digestion
- Submandibular glands release protease for protein digestion
- Sublingual glands release lipase for fat digestion
Enzymes contained in unprocessed foods and those exposed to temperatures under 118F, also get to work with the help of chewing.
For a closer look at the location of these glands, here’s an image.
Image Credit: OpenStax College – Anatomy & Physiology, Connexions Web site.
http://cnx.org/content/col11496/1.6/, Jun 19, 2013.
Lingual tonsils at the rear of our tongue are responsible for evaluating anything we eat, drink or inhale.
These lesser-known tonsils are full of immune cells evaluating inbound traffic in our mouths ensuring foreign substances are not permitted.
Palatine tonsils, the ones often removed, act as a boot camp for our immune cells to learn how to recognize friend vs. foe.
Generally only removed after seven years of age, tonsils are part of Waldeyer’s tonsilar ring. This ring of immunity is compromised of our tonsils, ears, nose and throat and can swell during times of infection.
The esophagus is a long tube connecting our mouth to our stomach and along with the pharynx is generally not involved in digestion.
Rather than taking the shortest and most efficient route, the esophagus enters the stomach from the right hand side instead of the top.
Why would it do this you ask?
Decreased Abdominal Pressure
A side ways connection decreases the amount of pressure on our abdomen during walking or laughing. If the connection were linear you may be forced to let a burp escape when walking after a heavy meal, or
According to the natural laws of physics, air rises vertically and sits at the top of the stomach. This air does not think to look for a sideways exit and if it builds up, may cause bloating.
Did you know our stomach starts above our navel?
It extends from below our left nipple and the bottom of our right ribcage.
The heart and lungs sit above our stomach making it difficult to breathe after a generous holiday dinner!
In addition to a side entrance, the stomach is also wider on one end than the other.
It folds to accommodate the unusual shape and allows a separation of working areas – one for liquids and one for food.
In most cases, liquids take the express lane to the small intestine without minimal digestive work and pass thru the shorter side of our stomach.
Food ends up in the larger area of our stomach to be more extensively processed before moving to the small intestine.
It takes approximately 45 minutes after the stomach stretches for Hydrochloric Acid to be generated, starting the process of protein digestion via pepsin.
When you need antacids for indigestion, the solution is not to decrease or block acid.
In this case more acid is needed, not less.
The stomach’s roles is to sterilize chewed food with Hydrochloric Acid formed from ingredients in our blood and continue chemical digestion.
The Small Intestine
Don’t be deceived by it’s name – the small intestine can be between 10 and 20 feet or 3 to 6 meters long!
By winding around our abdomen, the surface area increased maximizing digestive capabilities.
The small intestine contains ‘chyme’ or the semi digested mush from our stomach.
This is where, based on its components, different digestive enzymes are released to further break down food into smaller molecules.
The small intestine comprises three distinct regions:
The duodenum is the first and shortest part of the small intestine.
It receives liver, pancreas and gallbladder enzymes to continue breaking down chyme.
By the time it arrives at the ileum approximately 90% of nutrients have been extracted from the chyme.
The small intestine is home to many fingerlike projections called villi making the surface look smooth and velvety to the naked eye.
On closer examination, you would see villi have microvilli – villi upon villi!
Each square inch contains 20000 villi, or 30 per square millimeter!
Each of these villi contains capillaries to absorb the small post digestion molecules. These molecules are rapidly absorbed in our bloodstream to provide energy, repair and build new cells and keep producing the hormones we need to stay alive.
The presence of certain unfriendly gut bacteria, stress and certain diseases can create openings in our gut wall.
Often referred to as leaky gut, these openings allow partly digested food molecules into our blood system.
Our immune system must now complete digestion as it’s outside the scope of our digestive system.
The Large Intestine
Next stop on the digestion journey – the large intestine, is comprised of:
- Colon – transverse, ascending and descending
- Rectum and Anal Canal
The colon – also referred to as the large intestine contains most of the bacteria in our body. These may be beneficial and opportunistic bacteria depending on our metabolism, food choices, and ability to digest and eliminate food.
Consumption of simple sugars is THE easiest way to ensure the bad critters survive and actually flourish!
By providing the perfect food source, bacteria multiply and create waste products and toxins. These waste products and toxins are recognized as the trigger for allergies, acne, psoriasis, arthritis and joint pain, headaches, depression and anxiety.
A healthy appendix is used to reboot our digestive system.
It ensures a supply of healthy gut bacteria when an illness rids us of the existing bacteria.
Unless it ruptures or becomes infected, the appendix keeps to itself and is a great insurance policy should our gut bacteria need a boost.
Finally the anal canal and rectum, lead waste products from digestion to the outside world.
What Have We Learned?
Digestion is physical chemical and environmental and it is influenced by:
- Food choices
- Cooking methods
- Chewing thoroughly
- Eating speed
- Stress levels
- Availability of digestive enzymes.
Digestion is complex and is “the great secret of life.” 
Note: This article is an overview of the digestive processes of the human body.
Check back here or contact Cheryl for more detailed articles in the future.
 Giulia Enders and Jill Enders, “Gut: The Inside Story on Our Body’s Most Underrated Organ”, Greystone Books, Canada, 2015 p23
 Loomis, Howard Jr, “The Enzyme Advantage” 21st Century Nutrition Publishing, 2015 p69
 Giulia Enders and Jill Enders, “Gut: The Inside Story on Our Body’s Most Underrated Organ”, Greystone Books, Canada, 2015 p41
 Gottschall, Elaine “Breaking the Vicious Cycle” Kirkton Press, 1994, p21