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Where Does Food Go?

Once we’ve satisfied our craving,

what does our food do for us?

When you chow down on your morning

cereal or polish off a slice of pizza, you send

your meal on a great adventure through your

digestive system. Starting in your mouth,

your teeth chew up your food, and then your

saliva’s enzymes (special proteins that help in

chemical reactions) soften it. Once the food

is easy to swallow, those morsels cruise on

down your esophagus, a tube that connects

your throat to your stomach.

Your stomach breaks down your food

even more, using its strong muscles and

enzyme-rich juices to churn your snack into

a soupy mix. Once properly mushified, this

substance flows into the small intestine,

a coiled tube that, if it were unstretched,

would be a whopping 22 feet (6.7 m) long!

Here, food becomes a liquid, and the walls

of the small intestine begin absorbing all the

nutrients, sugars, proteins, and fats into your

bloodstream. The pancreas and liver aid in

this process by sending in juices that help

break down proteins, fats, and some carbs.

Once the good stuff is squeezed out of

your food and passed into your bloodstream,

the blood carries it to your liver for further

processing. Then it goes all over your

body—transporting simple sugars (glucose)

and fatty acids for energy, amino acids for

growth, and nutrients for other tasks.

Glucose can

,

t make it into all of your

cells on its own, however. To enter muscle

and fat cells, it needs help from a special

hormone, called insulin. (People who have

problems with insulin are diabetic.) Your

pancreas creates insulin and releases it

when it discovers that your blood has a lot of

glucose in it. Insulin then travels to your cells

and acts like a key in a lock, telling the cells

to let the glucose in. The cells convert the

glucose to energy via a process called cellular

respiration, breaking the glucose down into

carbon dioxide and water, and then using the

energy for its cell activities.

What about the leftover liquid in the

small intestine? It goes to the large intestine

and gets worked on by bacteria. The large

intestine also absorbs water and lingering

minerals that may be of use until there’s

nothing left but—you guessed it—poop!

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