What did you eat for breakfast today? And happened to the food? Every bite of food goes on a looonnnnng journey through your digestive system. So, where exactly is the food going? The digestive system has a series of tunnels with a super long name – the gastrointestinal tract.
The gastrointestinal (ga·strow·uhn·teh·stuh·nuhl) tract!
“Gastro” is the scientific name for “stomach”, and “intestinal” refers to the “intestines”. Because gastrointestinal tract has so many syllables, you can call it GI tract for short. You can even call it the digestive tract. With all of these nicknames, you can pick and choose your favorite!
Anyway, let’s take a close up look at food’s journey through the human gastrointestinal tract.
The gastrointestinal (GI) tract
Before going on a trip, it’s a good idea to look at a map so you don’t get lost!
This long journey starts at your face and goes all the way to your butt. Here are the destinations – also known as organs – that food will be visiting:
- Small intestines
- Large intestines
The mouth is the biggest hole in your face, and it’s also the very first part of the gastrointestinal tract!
With your mouth, you take big bites, tiny nibbles, and medium-sized chomps of food. As you chew, your teeth tear the food into smaller shreds.
Have you noticed that the inside of your mouth feels watery when you are hungry and eating? That’s because your mouth makes spit. Spit is a liquid with important chemicals that break down food. It also makes food slippery and easier to swallow.
Time for a ride down the first tunnel slide – the esophagus! The esophagus is a long tunnel in the middle of your neck and chest. It carries food from the back of your throat to the stomach. The key word here is “carries”, because food doesn’t slip or drop straight down the esophagus.
The walls of the esophagus have muscles that squeeze and push food through the esophagus tunnel. Squeeze, push, squeeze, push. Down, down, down. After a few seconds, food will make its way to the stomach.
Mix, mash, churn!
Food has arrived to the stretchiest part of your digestive tract, the stomach. While you eat, your stomach gets bigger as it fills up with food.
For the next few hours, the stomach muscles push food up, down, and around the stomach like a blender. The stomach also makes an acidic juice that transforms solid food pieces into a liquid paste.
When your stomach has finished its job, it gradually lets out the pasty food into the small intestines. Then, the stomach goes back to its regular, smaller size.
Here’s a peek at the stomach in action!
Hold on tight, because food just got to the twistiest part of the gastrointestinal tract!
In order to fit in your belly, the extremely long small intestines are folded up. But if you were to stretch out the small intestines, this long tunnel would measure around 22 feet (7 meters) long! That’s about as long as 22 spaghetti noodles laid out end-to-end. Speaking of spaghetti, the intestines sort of look like a pile of cooked noodles!
For the next few hours, the partially digested food is pushed through the small intestines. This where your body absorbs all of those good nutrients, like vitamins and minerals.
So much has happened already, but there’s still more work to do! Leftover food is like garbage to the body. Whatever the body can’t digest becomes waste that gradually travels through the large intestines.
Up, across, and down toward your bottom.
Over the next 1 to 2 days, as undigested food travels through the large intestines, water gets absorbed from the leftovers, while waste gradually turns to poop.
Whew! We made it to the finish line!
The destination at the very end of your gastrointestinal tract is called the anus.
Through this hole, waste from the intestines can leave your body out of your bottom and into a toilet or a diaper.
Goodbye, poop! The journey is finally over.
How does your gastrointestinal tract digest food?
How do chunks of food get smaller in your gastrointestinal tract? With a simple Tube-to-Tummy Experiment from the Human Body Learning Lab book, you can see how the stomach digests food.
Human Body Learning Lab is filled with kid-friendly science facts, memorable experiments, diverse realistic images, and practical health tips.