- Slides: 13
The Digestive System
The Digestive System The digestive system has Mouth three main functions: Esophagus 1. It breaks down food into particles that the body can use. 2. It absorbs nutrients into the blood. 3. It eliminates waste from the body.
The Digestive System Digestion can happen in two Mouth ways: Esophagus 1. Mechanical digestion: foods are physically broken down into smaller parts (like by teeth grinding, crushing, and breaking apart your food).
The Digestive System Digestion can happen in two ways: Mouth 2. Chemical digestion: Chemicals break Esophagus foods into smaller, simpler substances. Saliva moistens food to make it easier to swallow and also contains enzymes that begins to break down food. Enzymes are proteins that speeds up a chemical reaction.
The Digestive System • In the mouth, your teeth break down food into smaller pieces (mechanical digestion). After food is swallowed, it passes the epiglottis, a flap of tissue that covers the opening of the trachea to keep food out. Mouth Esophagus
The Digestive System • The food then moves to the esophagus. The esophagus is a smooth muscular tube that connect the mouth to the stomach and pushes food down Mouth Esophagus
The Digestive System • Most digestion happens Mouth in the stomach: • Mechanical digestion Esophagus occurs when the stomach muscles churn the food. • Chemical digestion happens when stomach acid breaks down food. Stomach
The Digestive System • Food remains in the stomach for several hours. The stomach digests the food into a liquid. This liquid enters the small intestine, a long muscular tube where the body absorbs nutrients. Mouth Esophagus Liver Gallbladder Stomach Pancreas Small intestine Large intestine Rectum
The Digestive System Mouth • The pancreas is a gland that releases Esophagus digestive enzymes and other chemicals into Liver the small intestine. Gallbladder Stomach Pancreas Small intestine Large intestine Rectum
The Digestive System • The liver is an organ that makes bile, a liquid that helps break down fat. • Bile is temporarily stored in the gall bladder until it is needed by the small intestine. Mouth Esophagus Liver Gallbladder Stomach Pancreas Small intestine Large intestine Rectum
The Digestive System Once food is digested, nutrients are absorbed through the wall of the small intestine. The folds of the small intestine called villi contain capillaries through which nutrients enters the bloodstream. Mouth Esophagus Liver Gallbladder Stomach Pancreas Small intestine Large intestine Rectum
The Digestive System The blood transports Mouth nutrients to all the Esophagus cells of the body. Any undigested material in the small intestine is Liver moved by peristalsis Small intestine (contractions) into the Large intestine large intestine. Gallbladder Stomach Pancreas Rectum
The Digestive System The large intestine Mouth belongs to the Esophagus digestive and the excretory systems. It’s role is to absorb Liver water and compact the Small intestine solid waste from the Large undigested material. intestine Gallbladder Stomach Pancreas Rectum