The body is science. The body is magic.
The most sophisticated model to date of what our cells look like, according to the internet. Looks right to me.
Our bodies perform dazzling, head-spinning magic.
Not to be dramatic, but the more I learn about the systems and functions of the body, the more blown away. I’m shocked that most of us actually continue to live on each day. It’s like, so many things actually have to go right at each moment. And while I’m someone who could turn this sentiment into an insane spinning wheel of anxiety, I’m choosing to take the approach of feeling awe and appreciation for the fact that things mostly do go right.
What’s fueling my awe and appreciation currently is this: I’m enrolled in a six month online nutrition course. The course is designed to give a detailed overview of nutritional science while also teaching students how to interpret diet news and make informed decisions for their own personal health. I invested in it late summer, thinking it’d be a good way to spend time during winter-pandemic.
The first of six classes covered the digestive system and how it relates to nutrition. Digestion is the process that extracts from the outside world, turning food into energy and nutrients that our body uses to live.
Here’s a little 101 about the digestive system:
Before understanding how our digestive process works, it’s helpful to understand how it’s regulated. It’s regulated by our bodies’ autonomic nervous system, which has two parts.
The sympathetic system, otherwise known as “fight or flight.” The classic example here is “what happens to our bodies when we’re being chased by a bear in the wood.” A more modern, applicable example: “what happens to our bodies when we get a Slack notification from a colleague we are scared of.”
The parasympathetic system, otherwise known as “rest and digest” or “feed and breed.” This system gets activated when we’re reading on the beach, or cuddling with a pet.
These two systems are first activated by neurons in our brain, which interpret what’s happening in our world around us and then sends off the right systems to activate depending on what we’re experiencing.
Digestion works when our body is in a parasympathetic, “rest and digest” state.
A simplified version of what the body does when we’re in a parasympathetic state to digest the food we eat:
First, before we even put the food in our mouths, each organ involved in digestion gets ready. It’s called the cephalic phase. Our salivary glands produce saliva, our sphincters tighten, our stomach creates an acidic environment, our pancreas creates insulin to be at the ready, among many other things. I like to imagine each organ as an excited actor at their local theater’s production of “Digestion” and the cephalic phase is when the director yells “PLACES EVERYBODYYYYYY.”
When food enters our mouth, the saliva we’ve produced gets to work, creating mucus that help coat our esophaguses and GI tracts as well as an antibacterial agent as a first line of defense against whatever we’re about to put into our bodies. Our saliva also contains enzymes that start to break down the fats and starches in the food.
As we chew food, we break it down into smaller pieces so that the saliva can coat each piece thoroughly.
Our esophageal sphincter stays closed until it’s time to swallow, at which point our esophagus creates waves of muscle contractions to bring the food down into the stomach.
Once in our stomachs, the food is once again met by a bunch of enzymes that break down the food into things our bodies use for energy (ex: lipase is an enzyme that breaks down fat into fatty acids, which our bodies know how to use) and introduces more acids which help to kill bacteria.
The small intestine comes next. By this point, it’s ready to get to work with the hormones, created by pancreas, as well as bile from your gallbladder and liver, to complete the breakdown of the food. The small intestine is lined with little finger-like projections called villi, which essentially grab the nutrients that are created at this stage and move them into the bloodstream.
The small intestine moves what’s left into the large intestine, which absorbs water and salts before passing the remaining out of the anus (Poop.. I’m talking about the poop).
I mean, isn’t this insanely complicated? And yet these things happen while we’re going about our day. When I pause to learn and think about how complicated my body is and how hard it works for me, I start to appreciate it more. I want to support it to continue to function at its best and give me what I need.
How can I support my body? To start, I can try to make sure I’m in a relaxed, parasympathetic state before eating. I can turn my phone over (or god forbid put it away), and I can take a few conscious breaths while looking at my plate before taking a bite. I can give myself a beat to actually realize I’m about to eat, and then I can try to enjoy the sensations—flavors, smells, textures—of the food in front of me. I can feel gratitude for having food to eat, and for having a magical body that knows just what to do.
