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The liver

hepatic; liver; amino; acids; glucose; cholesterol; organ; urea;


What is the liver?

The liver is the largest organ inside your body.

  • It looks like a reddish brown wedge with 2 different parts, or lobes, of different sizes. The right lobe is a lot bigger than the left lobe.
  • It weighs about 1.4 kg when you are fully grown.
  • It lies on the right hand side of your abdominal cavity (say ab-dom-in-al kav-it-ee) underneath the diaphragm (say dye-a –fram) and behind the ribs.
    cross section of the liver
  • Two large blood vessels called the hepatic artery (say hep-attic art-er-ee) and the portal vein (say por-tal vayn) carry blood to the liver.
    • The hepatic artery brings oxygen-rich blood straight from the heart through the aorta.
    • The portal vein also brings blood but this is carrying digested food from the small intestine (say in-test-een).
  • As these blood vessels come into the liver they branch out and get smaller until they end in incredibly tiny capillaries. Each capillary (say cap-ill-aree) leads to a lobule (say lob-yule) and each lobule is made up of hepatic cells. These are the basic cells of the liver and they do the most amazing things for your body.

What does the liver do?

The liver performs over 500 different functions! In fact it is so important that we cannot live without our liver. Maybe if you become a medical doctor you will learn about all of them, but right now we are going to look at the main things that the liver does.

Let's look at the main three

Your liver acts as a chemical processing factory to change most of the food that you eat into stuff that your body can use, and it gets rid of the things that are no use or are toxic (this word means harmful to your body.)

  1. Your liver makes and stores fuel

    Your liver makes glucose from carbohydrates (say car-bow-hi-drates) that you eat, such as ones in bread, fruit and dairy products. Some of this glucose travels in the blood to the rest of the body where it is used for energy. 

    Some of the glucose is stored in the liver as glycogen (say gly-co-jen) and it is there until your body needs to use extra energy, like when you have to run fast, react quickly or have to work your body hard for a long time. running fast, reacting quickly

    It also helps to keep blood glucose at the right levels.
  2. Your liver cleans your blood

    removing waste from your bodyYour liver takes toxins out of your blood. These may have been made by your body when breaking down proteins (say pro-teens), or been brought into your body through breathing or ingesting (say in-jest-ing) (this means taking into your body) something like alcohol, drugs or other harmful substances.

    Your liver sorts things out and changes them chemically into what your body can use and turns what can't be used into something that dissolves in blood so that it can be carried to the kidneys. For example the liver makes urea (say you-rear) from parts of proteins that can't be used. It is poisonous so the body has to remove it. Blood collects this urea from the liver and sends it to the kidneys. They filter urea from the blood and it is then expelled from the body as waste in your urine. (See Your waste disposal system if you want to know more about this.)

    Drinking too much alcohol for a long time can damage the liver so badly that it cannot do its job. This is called cirrhosis (say si-row-sis).
  3. Your liver makes bile which travels from the liver into the small intestine digesting fats in food - like burgers

    Bile is a digestive juice which helps the body absorb fat from the gut into the bloodstream. The liver makes this thick, yellow-green substance then stores it in the gall bladder until the body needs some to digest fats.

    Some other jobs that your liver does

    • Breaking proteins down into amino acids (say am-i-no a-sids).
    • Storing vitamins and minerals - A, D, K and B12, and iron.
    • Producing cholesterol (say kol-est-er-ol): about 80% of the cholesterol in your body is made by the liver from other fats that you eat. Cholesterol is a fat that your body needs for normal growth and health. Too much can be bad for your arteries, they can get clogged up which makes the heart have to work too hard.
    • Breaking down the ingredients in medicines, eg painkillers so that your body can quickly use them to make you feel better.
    • Helping with blood clotting so that when you cut yourself you don't bleed very long before the blood clots and stops the bleeding.


    Some infections can harm the liver so that it cannot work well. This is called hepatitis. Hepatitis A, Hepatitis B and Hepatitis C are some of the illnesses that are caused by viruses. Kids nowadays get immunised against Hepatitis B when they are babies or when they are in Year 8 at school. There is a topic about Hepatitis B if you want to know more.

    Some interesting facts about the liver

    • your liver can regenerate itselfYour liver consists of 96% water. (The water is inside the cells and in blood.)
    • Medical words to do with the liver often have hepato - or hepatic in them. This comes from the Greek word for liver.
    • Your liver can regenerate (re-build) itself. Even if only 25% of it is still healthy your liver can regenerate itself into a full liver again!
    • Your liver is bigger than your brain.

    Dr Kim says

    Dr KimYour liver works very hard to keep you healthy. You can help it by eating healthy food, drinking water, exercising regularly to keep your body systems working well, and staying clear of alcohol.

    the liverIf your liver is not working well your eyes and skin may look yellow. Then it is time to visit your doctor straight away. You cannot live without your liver so look after it and it will look after you.

    There were a lot of big words in this topic. Hope you have learned how to say them as well as what they all mean!

    the liver

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    We've provided this information to help you to understand important things about staying healthy and happy. However, if you feel sick or unhappy, it is important to tell your mum or dad, a teacher or another grown-up.


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