You eat a meal. And then a bit later… you do a poo! But what happens in between? NG KiDS takes a juicy journey down through your digestive system to find out where your grub goes…

It takes around 24 hours for your dinner to wind its way through the nine-metre-long digestive tract. On its trip, it’s mixed with acids and digestive juices, and squeezed and squelched until all the nutrients that the body needs are absorbed. Then, the smelly leftovers, along with billions of dead bacteria, are ready to exit the body. Plop! Let’s follow your food to learn about the brilliant bits of our bodies that make up the digestive system.

digestive system


It all starts here! Up to 28 strong teeth* chomp your food, breaking it into smaller bits. Meanwhile, the tongue keeps moving the food around, shifting it to the type of teeth that will be best at munching it. It also squeezes the chewed grub into swallowable lumps, pushing them back towards the throat. Gulp!

Fast fact
: When you swallow, a little flap of cartilage called the epiglottis closes off the windpipe so food doesn’t go down there by mistake.

*Most grown-ups have 32 teeth. You usually grow four ‘wisdom’ teeth between the ages of 17 and 24.


Also known as the gullet, this 25cm-long tube contracts to shift chewed food down to your stomach. The squeezing motion of the muscles is called peristalsis and it occurs throughout the digestive system. A slimy mucus is also oozed from the oesophagus to help the food on its way. Easy does it!

Fast fact: Thanks to peristalsis, food would get to your stomach even if you were standing on your head!


Next stop – the stomach! This stretchy muscular bag is about the size of a tennis ball when it’s empty, but expands to the size of a football to store a massive meal. As soon as food plops inside, the stomach lining releases digestive juices and acid that break down the food even more, killing harmful bacteria. Muscles slosh and squelch the food together with the juices until it becomes a sloppy soup called chyme that’s ready to be squirted into the small intestine

Fast fact: The acid in your stomach is so strong it could dissolve an iron nail!* To stop your stomach digesting itself, it’s lined with a protective mucus, and your stomach cells are replaced every few days.

* Please do not eat a nail. Ever.


Despite the name, this section of your digestive tract is really not that small – it’s a whopping 6.5-metres-long! It’s in this 3cm-wide tube that all the nutrients in your mushed-up food pass through the small-intestine lining into the blood. Once all the goodness is gone, the sloppy mixture passes to the next part of the intestines…

Fast fact: The lining of the small intestine is covered with teeny finger-like bumps called “villi”. They give the lining a large surface area to help with absorption.

digestive system villi in small intestine


More than twice as wide as the small intestine, but only 1.5-metres-long, the job of the large intestine is to soak up water, salts and minerals from the indigestible leftovers. Finally, the remaining semi-solid waste, called faeces, travels to the lower colon and rectum for storage. When you go to the loo, a ring of muscle called the anus relaxes to allow the poo out! Super and stinky!

Fast fact: Your small and large intestines together are known as your bowels!


Most of the slimy liquid in your mouth is produced by three pairs of salivary glands. This saliva moistens food, making it easier to swallow. It’s also full of chemicals called enzymes that help to break down food. Amazingly, just the smell of good grub can make your mouth start to water!

Fast fact: Your salivary glands can produce up to six cups of saliva per day. Squelch!


This busy brown organ is your largest internal organ and has about 500 different jobs! It’s like a chemical processing factory – blood carries nutrients there from the small intestine, then the liver decides what to do with them. It also gets rid of toxins (substances that can be harmful to the body), recycles old blood cells, makes bile and other digestive juices, and produces, stores and releases glucose (to give you energy).

Fast fact: About one third of the body’s blood flows through the liver every minute!

digestive system bile


The role of this green, pear-shaped organ is to store bile and make it thicker and stronger before adding it to the small intestine.


Your pancreas makes chemicals called enzymes which help digest nutrients in your food. It also makes insulin, a hormone which helps control your blood sugar levels.


Doctors used to think that this thin little organ was useless – a leftover body part from early humans. But today it’s thought that the appendix stores “good bacteria” that can help your digestive system work again after you’ve been poorly.

digestive system rumbling tummies

Images taken from SuperHuman Encyclopedia, published by DK priced £16.99. Find out more at With thanks to Dr Dewi Byrne.




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  • raiah

    I love the article!

  • jack nadoff

    Thanks for all this information about the human body,its very interesting.

  • Cool but i still think the stomach can expand more than a football.

  • dragon

    i love science!

  • dragon

    this is epic LOL !

  • Ari12

    That is so cool! I've always wanted to see what the appendix looks like because my father got appendicitis.

  • nathanbuttomley

    cool yo

  • nathanbottomley

    my nan is awsome

  • yournan

    lol rekt

  • legand


  • nathanbottomley

    lol my nan

  • vunu

    very nice pics!!

  • abel

    asum e

  • Ng


  • awhyeahhhhh

    Now this just feels right.

  • Grace678984

    It is interesting but that is another word for poo

  • Rheya

    Wow! this was a crazy website BTW love my avatar!

  • spooki



    hi f.r.i.e.n.d.s is awesome i like season 8 and emma is cute. MOO

  • xaqjajahzhs

    what are the two types of digestion? please help!!!!!

  • PengiunMaster42

    That really happens in my body?!?

  • broboy

    weird but true!

  • broboy

    this is so weird but cool

  • DinosaursForeva


  • Jel

    Wow! I never knew what happened when food got digested


    this is sooooooooooo interesting I used this for homework about the rainforest :)

  • larab


  • B-l-u-e2626

    Helpful facts

  • Ellie-Elephant


  • BEN

    These facts are cool

  • Aishah

    that is sooooo cool

  • geff

    that is nice

  • xXx_sweglord_xXx

    I am hungry





  • duck

    this is so good Im at school,

  • Aimz

    wow I did not know all that, but now I do, yay!!!

  • Nicolette

    Wow, thats awesome!

  • science


  • A6--3

    Wow!! Really interesting fact about tummy rumbles! They have explained the facts thouroughly which makes it really interesting

  • superboy1000

    this is awesome

  • superboy1000

    hi everybody i think this is cool do you

  • caleb

    I did not know that

  • 12344


  • Rosie

    I just learn this and it was great!

  • Funkymonkey123

    That is ssssssooooooooo interesting!!!!! I really, really want to be a Doctor when I grow up

  • Rose

    That is so so so so so good I never new that

  • wolE


  • superkid1111

    its amazing everyone has that inside them

  • Jahnavi

    I did not know that, it was cool!

  • ameesha

    I was thinking what to do for school when I thought why not this it got a very good explanation of how you digest your food

  • Ria

    I am doing a bit about the body so this was very useful.

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