ORGANS – THE LIVER HUMAN BODY
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 underneath the diaphragm and behind the ribs. • Two large blood vessels called the hepatic artery (say hep-attic art-er-ee) and the portal vein (say por-talvayn) 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.
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 all about them but right now we are going to look at the main things that the liver does. • 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.) • 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 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. It also helps to keep blood glucose at the right levels.
Your liver cleans your blood Your liver takes toxins out of your blood. These may have been made by your body when breaking down proteins, or been brought into your body through breathing or ingesting 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 • Your liver makes bile which travels from the liver into the small intestine. 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. • Storing vitamins and minerals A, D, K and B12. • Producing cholesterol: 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.
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. • Your liver consists of 96% water. • Medical words to do with the liver often have hepato - or hepatic in them. • 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 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. • If 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.