Hello again mini medics and welcome to my blog post about building my very own human body.
Today Nurse Nanobot and I made a digestive system for our body.
Press the play button above to listen to us explore the world of the dazzling digestion, and also read loads of interesting facts below!
From the mouth to the bum, your digestive system allows your body to get the nutrients and energy it needs from the food you eat, and then gets rid of the left overs when you go to the toilet!
How it Works
The whole process of digestion starts with your mouth. Chewing food isn’t just to enjoy the taste – it breaks the food into small pieces and with help from saliva moves food down your oesophagus where ring like muscles squeeze it along on it way into your stomach.
Your stomach, which is like a stretchy bag, has three jobs – to store food that you’ve eaten, to break it down further with gastric juices, and to slowly empty the liquid into the small intestine.
Gastric juices don’t just dissolve food – they also kill bacteria and so can help stop you getting poorly.
The small intestine is like a squidgy pipe and at more than 5 metres long is longer than the average car!
The food moves slowly along, getting broken down further so your body can absorb all the vitamins, minerals, proteins, carbohydrates and fats. It can take about four hours for a meal to move all the way through.
Your pancreas sends juices to help get the nutrients out of the food and into the blood.
The nutrient-rich blood then travels to your liver, whilst the waste carries on through the gut to the large intestine, which is weird as its actually only a third of the length of the small intestine!
It is a squash and a squeeze in there. As food goes along the colon, which is part of the large intestine, moisture is removed and it’s the last chance for nutrients to be slurped away into the bloodstream.
What’s left gets chunkier and harder as all the waste products stick together.
And you know what we call the waste product at this stage? Its scientific term is faeces, you’ll know it as poo. The large intestine pushes the poo into the rectum, which is the very last stop on the digestive tract.
When the body gives a signal, the muscles in the rectum push the poo out through the anus – the hole in your bottom, and that’s the end of the food’s journey!
What Happens to the Water?
Now all that water that’s been slurped out of the food has to go somewhere and there are several organs whose job is to do just this.
Together they are know n as the Urinary Tract and this is made up of the kidneys, ureters, bladder and the urethra.
You have two kidneys – they’re about 12 centimetres long and they’re round the back, just under your ribs.
Kidneys are always busy – like the liver their main job is filtering impurities out, which they do so through a million tiny filters called nephrons. They make sure that your blood has just the right amount of water, topping it up or taking it away as needed.
The waste liquid, which is called urine, is sent through tubes called ureters to your bladder. You probably know urine better as wee.
If you’ve had a look in the toilet you’ll know it can be dark or light yellow. The colour depends how much or little water is in the urine – like a drink of squash, when there is more water the squash is lighter, and when there is less, the squash is darker.
As part of our digestive system, we also had to lever in the liver. Did you know that it’s the largest solid organ in your body – when you’re a grown up it’s bigger than your head!
Nutrient-rich blood comes to the liver to be cleaned, and nasty toxic stuff is removed. That’s the main job of this clever organ.
But the liver also stores energy in the form of a sugar called glycogen, and produces clotting agents that help you heal when you’re hurt.
The liver also produces an important digestive liquid called bile which is squeezed into the intestines by the gall bladder to break up fat so it can be absorbed into the blood. Bile is also what makes your poo brown!
Nurse Nanobot’s Orrible Old Anatomy Fact
In 1927 a Canadian woman complained of stomach pains and was found by doctors to have swallowed over 3,500 metal objects, including 947 bent pins.
I am sure you are all very sensible and never put anything dangerous in your mouths. But remember, you can be sensible too in other ways – drink plenty of water and have lots of fruit and vegetables to keep your digestion moving.
If all you chomp is chocolate things, your tummy will be in trouble!
Burping and Farting aren’t very polite but they are a helpful way the body can get rid of gas that you’ve swallowed.
With every mouthful of food, a bit of air gets in too. Fizzy drinks in particular contain loads of bubbles that cause burps and certain foods like beans and onions produce more gas in the gut that is likely to form a fart.
The gas in burps tends to be mainly oxygen, nitrogen or carbon dioxide. In farts it contains much smellier gas like methane, because of all the chemical activity down there in your stomach.
That’s it for today. Join me and Nurse Nanobot on our next blog, where we will tell you what happened when we looked at how our body will protect itself from germs.
You can listen to Professor Hallux on: