Digesting Information

It’s been a whirlwind of work and school recently, with much less time than I’d like devoted to baking, cooking and reading things not related to gastrointestinal processes (not the most appetizing subject). But our unit on digestion is coming to an end and I realize that by some miracle of osmosis I have learned a lot about how to sustain, repair and maintain proper digestion.

In short, our digestive system is sort of like a second skin: it controls the entry of substances from the outside world into our bodies. Digestion begins in the brain when we are excitied by food-related stimuli. In response, the brain sends hormonal signals down to the stomach, liver, pancreas and intestine, alerting them to prepare for an influx of food. Then, as soon as food enters you mouth it begins to be broken down by the enzymes in your saliva. Carbohydrates in particular, are significantly broken down in the mouth, which is part of why they affect your blook sugar and energy level so much more quickly that proteins and fats.

Next the food passes through the esophogus and into the stomach, where hydrochloric acid and pepsinogen are secreted to continue the process of breaking down the food. Pepsinogen is a precursor to pepsin, an enzyme that breaks down protein. Of course our muscle cells, including our stomach, are made largely of protein, so releasing enzymes that break down protein into an organ made of protein doesn’t really seem like the best idea. But, here’s where it get’s cool—pepsinogen is an inactive form of pepsin. It only turns into pepsin when it comes into contact with HCl, and the stomach only releases HCl when it’s mucosal layer is sufficient to protect itself – part of the whole hormonal signal response! If you do not currently have a oozing hole in place of your stomach, give it a pat and a “thank you” for the good work.

After passing through the stomach, the partially digested food passes into the small intestine. Bile (from the liver) and pancreatic enzymes (from—you guessed it—the pancreas) are mixed in, as is bicoarbonate (also from the pancreas) to alkalize all the stomach acid. It is really in the small intestine where the nutrients from your food are absorbed into your body. If your small intestine isn’t functioning properly, it doesn’t matter how healthfully you eat—you won’t fullyabsorb the nutrients.