top of page


Bacteria These are very small organisms that are all around us and on our skin. Some bacteria can cause disease. Most are harmless. Some, for example those that live in the intestine, are beneficial and help to break down the food during digestion.

Bile is digestive juice produced by the liver. It is a yellow-green colour, quite thick and is stored in the gallbladder until the body needs it. It helps to break down fats in the small intestine and also carries away waste products formed in the liver.  

Bladder This is where the urine (pee) is stored until you pass it i.e. into a nappy or toilet for example. In an adult, the bladder might be able to hold 0.5 litres of urine before there is a feeling to pass it. 


Blood is the red liquid that flows around the inside of your body and you can see it if you cut yourself. It flows like a river through tiny elastic tubes (known as vessels) around your body pumped along by the heart. It takes things like the air that we breathe and the food that we eat to different parts of the body to help keep us alive. It also plays an important role in protecting us against infection. Known as 'Brucey Blood' in some of the Busy Body Books. 

Blood vessels are used to carry the blood around the body. There are three main types – veins, arteries and capillaries. Blood is kept flowing by pumping of the heart; by muscles in artery and vein walls; and by a decrease in pressure (liquids flow from high to low pressure). The movement of blood around the body and the heart is known as circulation. It takes less than 60 seconds for your heart to pump blood to every cell in your body!

Bones There are more than 300 bones in a baby's skeleton, but as we grow some of these bones fuse together to make bigger bones, so that by adulthood we only have 206. They form a frame called the skeleton which gives the body shape, protects the body organs (for example the heart), and provides a solid base for the muscles to work against. 

Brain This is found inside your head. It controls most of the things your body does like moving your arms and legs; or feel things like if you have pain, something is hot, or you need to use the toilet. It controls things like emotion, speech and thought.

Calcium is soft and white. It is used for making strong bones and teeth. It is also used to keep the muscles healthy and is in the blood to help with clotting (for example forms the sticky lump you see when you cut yourself which stops you bleeding too much). It can be found in many things including milk, bread, eggs and vegetables.

Carbohydrate These are found in certain kinds of food such as sugar, cereals, bread, pasta and potatoes. It provides the body with energy. If you have more than you need for energy in your body, it is changed into fat

Cells These are very tiny. They are the smallest part of a plant or animal, each one containing millions of cells. The human body contains billions of these and are essential to perform the complex tasks necessary for life.

Cereals These are made from grain. Examples of these are wheat, corn or rice. It is used in breakfast cereal.

Colon See under ‘Large Intestine’.

Diabetes (mellitus) is a condition in which the body does not produce enough insulin to be able to control the level of glucose in the blood. 

Digest / Digestion is the process of food and fluids being moved from the throat to the rectum. The process breaks down food and makes it into things that the body can use; for example protein being used to make muscle.

Energy One example of this is the body having the strength and power to do active things. Another is the way the eye converts light energy into electrical nerve impulses to make vision possible. 

Electrolytes These are tiny and can be found in the blood. They play a very important role in keeping the body healthy. If you become ill and lose a lot of fluid (like vomiting for example), they become unbalanced which can then stop your body working correctly. Sometimes people need medical help to get the electrolytes balanced again. 

External Sphincter External means outside. Sphincter is a ring of muscle that can be found around an opening. In the story about the kidneys with Matthew, the ring of muscle is on the outside of the bladder. It stays tight and keeps the urine (pee) in your bladder until you are ready to use the toilet. When it gets the message that you want to use the toilet, it relaxes and lets the urine out…unless of course you are like Matthew and wait toooooo long! 

Fat comes in many forms. One form is contained in foods such as meat, cheese, oil, butter and nuts. It contains important vitamins needed for the body to function. Fat is an important part of a healthy diet especially for little children as it is needed to develop the nervous system and brain correctly. It can be used for energy, to help keep you warm and to form body fat. Body fat lies beneath the skin and around some of the internal organs. Excess amounts of fat are stored under the skin in obesity.

Fat Cells – Most of your body fat cells are found just underneath your skin. By the time you are an adult you might not make any more fat cells, they just get bigger or smaller! They help to maintain body energy levels and store energy in the form of lipids. If the energy in the cells are used by the body they get smaller; if you eat more than you need the body stores some of this in the fat cells and so they get bigger.


Fibre is bits of plants or seeds that your body cannot digest. Most vegetables and fruits contain fibre. It is also found in foods like cereals and wholemeal bread. It is very important as it helps food pass through your body. It assists with problems like constipation and other gastric problems. It can also help prevent cancers and reduce cholesterol levels. Intestine The tubes through which food passes from your stomach to the rectum. There is the small intestine and the large intestine.

Gall bladder – This is a pear-shaped sack, just below your liver. Bile, which is produced by the liver, is stored in the gall bladder.

Gastric Juices are secreted from glands lining the stomach. It is used to break down food in the stomach and kill bacteria. It is the yellow stuff that comes up from your stomach sometimes if you vomit. Known as the 'yellow pool' in some of the Busy Body Books. 

Glucose is a type of sugar that gives you energy. Sugar is changed into glucose in the small intestine. It is naturally present in fruit. It is also produced during the digestive process of products like carbohydrates. It is carried to all the tissues in the body by the blood where it can be used for energy.

Glycogen - Glucose is the main type of fuel for our body cells. When there is extra glucose it can be stored in the liver and muscles. When it is stored in this way it is known as glycogen. If the body suddenly needs extra energy or the blood glucose level drops the glycogen is changed back into glucose and used by the body as fuel for the cells.

Heart This is found in your chest area. It is made of muscle and pumps the blood around your body…even when you are asleep! 


Hormones These are ‘chemical messengers’ which are transported by the blood to make certain parts of your body do something; for example insulin, which opens the cells so that the body can use glucose for energy.


Hospital  This is a place where sick or injured people are given medical or surgical treatment with specialized staff and equipment.


Insulin is a substance that most people produce naturally in their body. It controls the level of glucose in the blood and is essential in the process of glucose being absorbed into cells where it is converted into energy. It is made in the pancreas by a cluster of cells known as the ‘Islets of Langerhans’. In diabetes the body does not produce enough insulin to control the level of glucose in the body. It is one of many types of hormones in the body. Islets of Langerhans  see pancreas and insulin.

Islets of Langerhans  see pancreas and insulin.

Large Intestine is the shorter and second part of the intestine. It is made up of three parts - the caecum, colon, and rectum. It reabsorbs water, vitamins and salts (from the food that has already passed through the small intestine) into the blood stream. What is left is later passed as faeces (‘poo’) into the toilet.

Ketones These are produced when the body starts using fat instead of carbohydrates for energy. If your blood glucose is normal and you are losing weight, it can be normal to have ketones sometimes. High levels can be found in diabetes when the body cannot use glucose normally. When they are found in the urine this is known as ketonuria.

Kidney There are usually 2 of these in a body but you can live perfectly normal with just one. They are bean shaped. Kidney’s help keep the blood clean and regulate the body’s fluid balance. Anything that isn’t needed is passed out of the body as urine. They also produce hormones which are used in the regulation of red blood cell production and blood pressure. 


Laboratory  A room or building where special equipment is kept to test things, or do experiments.

Liver - An organ inside your abdomen on the right hand side under your ribcage. It is wedge-shaped and a reddish-brown colour.  It does a lot of things to help keep your body healthy. The three main ones are:

 1. It cleans your blood which includes dealing with toxins or poisons you may have.

2. It stores energy in the form of a sugar called glycogen;

3. It produces an important liquid for the digestive system called bile.

Lungs Your lungs are the two sac like organs inside your chest which fill with air when you breathe in. They supply the body with an important gas known as oxygen and eliminate waste air including carbon dioxide. Plus they play an important role when you are talking. 


Microscope These are used to make very small things look bigger so that more detail can be seen.

Minerals These are found in foods. They are an essential part of a diet to maintain a healthy body. There are at least 20 and include calcium, iron, zinc, potassium and sodium. Some are only needed in tiny amounts. A well-balanced diet will provide all that you need. 


Muscle  There are three types: 1. Skeletal muscle is a piece of tissue inside your body which is connected to your bones by tendons and gives your body shape. You use these muscles to make your body move. 2. Smooth muscles are in the walls of internal organs for example the intestine (peristalsis action which moves the food along); blood vessels; and the bladder. 3. Cardiac muscle which helps keep the heart beating thousands of times a day.

Nephrons These are tiny little tubes found in the kidney. They filter the blood and also decide what can stay in the body and what needs to be sent to the bladder via the kidney. This process produces urine (pee). 

Obesity is when you have more body fat than is healthy for you. This is usually caused by having more food than the body needs. The food that we eat is partly used for energy. If we are eating more food than we require for the energy we use, this can get stored in the fat cells, making them bigger, therefore making the body fatter. 

Organ A part of your body that has a particular type of function for example your heart or the pancreas. 


Organism is a general term for an animal or plant, quite often so small that you cannot see it without using a microscope. Bacteria and viruses are disease-causing microorganisms.  


Oesophagus is the part of your body that carries the food from the throat to the stomach. It is part of the digestive tract. Powerful actions of the muscles in the wall of the oesophagus propel food and liquids down towards the stomach for digestion.  

Oxygen This is a gas and is in the air that we breathe. Animals and plants cannot live without oxygen. 

Pancreas A large long organ in your body that can be found behind your stomach. A tiny part of it called Islets of Langerhans makes insulin. This is used to regulate the level of glucose in the blood. The pancreas also makes digestive juices. These juices mix with your food in the small intestine before the food can then be used in various parts of the


Peristalsis – In the digestive system, peristalsis in the oesophagus (the pipe from your throat area to your stomach) moves food towards the stomach, even if the body is turned upside down! In the stomach, similar movements help mix food with gastric juices and move the food through the intestine. The final stage forces anything left after digestion, from the colon into the rectum.

Pharynx This is the part of the body that carries the food from the mouth to the oesophagus. It also plays an essential part in breathing and can change shape to help form speech sounds.


Protein is found in food and drink such as meat, eggs, milk, cereals and nuts. You need protein in order to grow and be healthy. It can also be used for heat and energy.


Pyloric Sphincter is the small ring of muscle around the opening at the bottom of the stomach. Its function is to control the movement of partially digested food into the small intestine.

Renal Artery Renal is a word used to describe things related to the kidneys. Arteries are the tubes that carry the blood from your heart to the rest of your body. So the ‘renal artery’ is the tube that carries the blood from your heart to the kidneys. 


Saliva is the liquid that forms in your mouth when you chew your food. It helps to break down the food; keeps the mouth moist; lubricates the food so that it is easier to swallow and helps the tongue and mouth to register taste.


Small Intestine is the first and longest part of the intestine. It is in 3 parts - the duodenum, jejunum, and ileum. Here bile and enzymes are mixed with the food to help break it up into tiny bits. This is where most of the important things in your food is digested and then taken (by the blood for example) to where it is needed in your body.


Stomach This is a bit like a sack and is between the oesophagus and the small intestine. Food is mixed together here with liquid known as gastric juices (the big yellow pool in some of the books) and partly digested before it moves into the small intestine.

Sugar is a sweet substance that is used to make food and drinks sweet. It can be found naturally in food such as apples and grapes. When you eat them, the body converts them into glucose and then it is used for energy. Too much can be bad for your body for example it can make you feel tired and rot your teeth.

Teeth - It is important to clean your teeth at least morning and evening to prevent them rotting (tooth decay). Without brushing, food and sugars from drinks (including fruit juice) can collect on the teeth and attract bacteria, which cause tooth decay, as well as gum disease.

Ureter The tube along which urine travels from the kidney to the bladder.


Urethra This is the tube that the urine (pee) travels along from the bladder to the outside of the body – when you have a pee. 


Urine Also known as pee. This is the pale yellow liquid that comes from the kidneys after cleaning the blood. It is kept in the bladder until you are ready to have a pee. Then it travels down the urethra and into a nappy or toilet for example.


Villi are soft tiny finger-like things that are on the inside walls of the small intestine. They provide a large surface area for the absorption of tiny bits of food from the intestine into the blood stream.


Vitamins These are found naturally in a lot of foods and are also added to other things like breakfast cereals. They are really important, as the body will not work properly if it does not get enough vitamins every day.


Wholemeal flour is made from the complete grain of the wheat plant, including the outer part. It is much better for you than ‘white’ flour as it has more good things like vitamins and protein. It takes the body longer to digest and because of this you become hungry less quickly after eating it compared to ‘white’ flour.


Ward This is a room in a hospital that usually has beds in it. It is used for people to have special medical treatments.


bottom of page