The digestive system breaks down food into smaller molecules and absorbs them into the circulatory system. It consists of the mouth, esophagus, stomach, liver, gallbladder, pancreas, small intestine, large intestine, rectum and anus. The mouth breaks down food with teeth and saliva. The esophagus transports food to the stomach using peristalsis. The stomach further breaks down food using acid and enzymes are sent to the small intestine where most digestion and absorption occurs. Undigested material then moves to the large intestine where water is absorbed before waste is excreted.
2. The Digestive System is the organ system which breaks down foodstuffs & absorbs them into the circulatory system. The digestive system consists of four different processes, ingestion, digestion, absorption and egestion. Ingestion is the taking of food into the body, digestion is when the food is broken down into smaller molecules, absorption is where the digested food is absorbed into the blood and egestion is when waste material is expelled from the body Function
3. Components Oesophagus (Food Pipe or Gullet) Mouth Stomach Liver Pancreas Gallbladder Small Intestine Large Intestine Rectum Appendix Anus
4. The mouth consists of the teeth, tongue and salivary glands. The teeth and tongue chop the food into smaller bits. By grinding the food, the surface area of the food is increased allowing more enzymes to come into contact with it. The salivary glands produce amylase, an enzyme which helps break down starch into sugars Mouth
5. The oesophagus contains muscles within its walls which contract to push food towards the stomach, this contraction is called “peristalsis”. Oesophagus
6. Food enters the stomach through the sphincter ring. The walls of the stomach contract to churn food into a liquid call “chyme”. Food is mixed with stomach acid so that enzymes have the correct acidity level to work effectively. Stomach acid also kills bacteria ingested with food. Stomach
7. The liver is the organ which produces a greenish-yellow liquid called bile. Bile is stored in the gallbladder. After eating, bile travels through the bile duct to the small intestine. It breaks up any fat in food into tiny pieces so it can be mixed with water liquids. This process is known as “emulsification”. Liver and Gallbladder
8. The pancreas produces pancreatic juice. This juice contains enzymes such as amylase, lipase and protease. Enzymes travel to the small intestine and assist with the breaking down of food. Amylase is used to break down starch into sugars, lipase is used to break down fat into glycerol and fatty acids and protease breaks down protein into peptides Pancreas
9. Food moves in the small intestine through peristalsis. The small intestine consists of three parts, the duodenum, the jejunum and the ileum. After bile has travelled to the duodenum and has broken up fat, lipases break the fat into smaller substances. Glands that are part of the ileum produce enzymes to break down food. Molecules of digested food pass through the walls of the small intestine and into your blood stream. Small Intestine
10. The large intestine is also made up of three parts, the colon, appendix and rectum. When food reaches the colon, most food has been digested, broken down and absorbed into your blood. Indigestible substances and water are left. The colon absorbs the water into your blood stream and the other substances remain. The semi solid substances are collected in the rectum and are then released from the body via the anus. Large Intestine
