The Journey Of The Cheese Sandwich! By Robert Harrington, 8D The Mouth • First the cheese sandwich will go into your mouth! In the mouth the teeth and jaw muscles will work together to break up the food into smaller pieces, this makes it easier to digest. • The saliva in your mouth allows you to taste the food. Saliva also contains an enzyme. An enzyme breaks down large molecules into small ones. The enzyme in saliva begins to break down starch as you chew. • The mouth is located at the lower part of your face above the chin. The Gullet/Oesophagus • The next part of the journey is in the gullet which is sometimes called oesophagus, it is a long tube in your neck. It can take as little as 2 seconds for the food to get down here! The walls of the gullet contract to move the food down into the stomach. The epiglottis closes the door to the windpipe so the food can’t go down there! The Stomach • Five seconds after swallowing your cheese sandwich it will enter the stomach! A lot of things happen in here! The hydrochloric acid in the stomach kills most of the germs in your food, it will also break down the protein in the cheese. The muscles in the stomach walls mush the cheese sandwich into a thick fluid called chyme. • The food is then forced through the pyloric sphincter into the small intestine. • The stomach looks a bit like a J shaped bag and it is located under the ribs. The Small Intestine • After going through the pyloric sphincter, the cheese sandwich enters the small intestine! In here the food is digested more into simple molecules and is also put into the blood. The simple molecules include glucose (from carbohydrates) which is in the bread, amino acids (from protein) which is in the cheese and fatty acids (from the fat). • There are lots of enzymes in the small intestine which are mixed with the food. • Remains of undigested food are squeezed by the muscles around the intestine, through to the large intestine. • The small intestine is located under the stomach and is followed by the large intestine. The Large Intestine • After going through the small intestine, any undigested food is squeezed into the large intestine. Mainly the fibres from fruit, vegetables and grain are found in here. • The waste material in the large intestine are called faeces. Too much water in the faeces causes diarrhoea, but too little water in the faeces causes constipation. • The large intestine is located around the small intestine and is connected to the rectum. The Rectum • This is the last part of the cheese sandwich’s journey. Faeces are stored in the rectum until you need to go to the toilet. • The rectum is the last 6 to 8 inches of the large intestine. Diagram of the Digestive System Mouth Food Groups • The 3 food groups in a cheese sandwich are: • Carbohydrates-this is found in the bread of the cheese sandwich and is mainly needed for energy. Carbohydrates should make up about 50% of your diet. • Protein-this is found in the cheese and is needed to help us grow. • Fat-this is also found in the cheese and provides needed energy, but eating too many fatty foods can be very unhealthy.