9 Interesting Facts About the Digestive System
I think it is safe to say we are all aware of having a digestive system, and that this system serves to break down food and assimilate nutrients to keep us going. Let’s take a closer look at some of the more interesting ways the digestive system gets it’s job done to keep us alive and nourished.
1. Random facts about the mouth:
- Without saliva, we would not be able to taste anything (yes, taste buds are responsible for your sense of taste, but without food being dissolved in saliva, the receptors on your tongue can’t detect food molecules.
- There are as many bacteria in the mouth as there are people on Earth.
- We produce about 37,854 litres of saliva during our lives – enough to fill two swimming pools.
2. You can digest food even while upside down!
Food doesn’t need gravity to move through the digestive system. Due to peristalsis, (the process of constriction and relaxation of muscles) you could eat standing on your head (not recommended), and food would still move from your mouth, through the esophagus, and into the stomach.
3. The stomach is lethal.
Cells along the inner wall of the stomach secrete roughly 2 liters (0.5 gallons) of hydrochloric acid each day, which helps kill bacteria and aids in digestion. Yes, THAT hydrochloric acid. The same powerful chemical which is commonly used to remove rust from steel sheets and coils, and is also found in some cleaning supplies.
As a protection from the corrosive acid, (essentially, protecting the stomach from digesting itself) the stomach lining has a thick coating of mucus. This mucus can’t buffer the digestive juices indefinitely, so the stomach produces a new coat of mucus every two weeks.
4. The enzymes in the digestive system are cousins of the enzymes in your laundry detergent.
Proteases, lipases, and amylases are three of the enzymes that we share with the detergent you wash your clothes in. Talk about multi-functional! In the body, proteases break down proteins, lipases break down fats and amylases break down carbohydrates.
5. Your small intestine, comprised of 3 parts, called the duodenum, jejunum and ileum:
- Is over 17 feet (6 meters) long.
- If unrolled and spread out has the surface area the size of a tennis court (2800 square feet) How can this be? This is how: The walls of the small intestine have folds, and also contain tiny projections of absorbent tissues called villi and microvilli (these are what absorb nutrients from food), which add to the total surface area. Spread it all out and get your racquet!
- Assimilates approximately 90% of the food you consume.
6. Your large intestine, or colon, which includes the cecum, ascending colon, transverse colon, descending colon, sigmoid colon and rectum:
- Is responsible for extracting water from waste material and hydrating the body.
- Over an entire lifetime, typically processes approximately 50 tons of food. Of course, it may be more or less depending on how much you eat. But, wow, 50 tons! Kinda makes you want to get a colonic, right?!
- Can act as a warehouse when needed. It’s possible that your colon might need a speck more time than usual to do its job moving things along. The colon is wide enough to accommodate two days worth of food if necessary. Now you’re really thinking about getting a colonic, right?!
7. What are farts made of? And how are they made?
Intestinal gas, or flatus, is a combination of swallowed air and the gasses produced by the fermentation of bacteria in the gastrointestinal tract. The digestive system cannot break down or absorb certain components of foods, so those substances simply get pushed along the tract, on their way to the large intestine. Herds of intestinal bacteria get right to work, releasing a variety of gases in the process, including carbon dioxide, hydrogen, methane and hydrogen sulfide (which gives some farts that rotten-egg stench). Gas is also released into the bloodstream, where it is later expired through the lungs. Eeew. Lung farts.
8. Let’s talk poop!
Stool is primarily 90% water. The other 10% is comprised of fiber, dead and live bacteria, other cells, and mucus. Soluble fiber (found in foods like beans and nuts) is broken down during digestion and forms a gel-like substance that becomes part of your poop.
Diarrhea is the result of stool passing too quickly through the large intestine, where most of the water content is absorbed. Constipation, on the other hand, is when it takes too long for stool to move along, and the lack of water makes it hard (literally!) to pass through to the rectum.
9. The Enteric Nervous System
I’ve left one of the most interesting facts about the digestive system for last. Often referred to as the body’s second brain, the enteric nervous system begins at the esophagus and ends at the anus. It contains approximately 100 million neurons and is so extensive that it can operate as an independent entity without input from our central nervous system, although they are in regular communication. The enteric nervous system also makes use of more than 30 neurotransmitters, most of which are identical to the ones found in the CNS, such as acetylcholine, dopamine, and serotonin. More than 90% of the body’s serotonin is in the gut, as well as about 50% of the body’s dopamine.
Stay tuned for next month’s blog for an in-depth look at this incredibly important, yet relatively unknown body system.
I hope these interesting digestive system facts lend clarity as to how our digestive system functions to process and utilize our food energy from the time we take that first bite of a delicious meal, to when we excrete the unusable parts.