The Digestive System PDF

The Digestive System Purpose of the Digestive System The purpose of the digestive system is to take in food, break it down into a useful form your cells can use (nutrients), and get those nutrients into your blood so that the circulatory system can take it to every cell in your body. What functions...

The Digestive System Purpose of the Digestive System The purpose of the digestive system is to take in food, break it down into a useful form your cells can use (nutrients), and get those nutrients into your blood so that the circulatory system can take it to every cell in your body. What functions as the fuel for the human body? The fuel your body needs to keep working is food. Parts of the Digestive System 1. Mouth 2. Esophagus 3. Stomach 4. Small Intestine 5. Large Intestine 6. Liver (A) 7. Gallbladder (B) 8. Pancreas (C) What is Digestion? Food is too big and complex for your body cells. It must be changed before your cells can use it. Digestion is a process that changes food into a form your cells can use. (nutrients). During digestion food is broken down into very small materials. Your body breaks down food two ways: Your body breaks down food two ways: Mechanical Digestion – Involves the tearing, crushing and mashing of food. Example: When you take a bite and chew it with your teeth or when your muscles of the stomach contract and relax. Chemical Digestion – When chemicals called enzymes help break down food into nutrients. What is the path food takes through your body? 1) Mouth – Food is Mouth v Esophagus v Stomach v Small Intestine v Large Intestine v Rectum/Anus shredded by the teeth and mixed with saliva. Saliva breaks down starches into simple sugars and softens and moistens the food. The tongue pushes the food, now called bolis, down the esophagus. Amylase- Enzyme present in the saliva that breakdowns starch Salivary gland What is the path food takes through your body? 2) Esophagus – The muscles in the esophagus push the bolis down into the stomach while its walls, lined with mucus, makes it easier for the food to slide down. Bolus- mixture of food and saliva that forms in the mouth during the process of chewing Peristalsis - series of wavelike muscle contractions of esophagus that move food through the digestive tract Mouth v Esophagus v Stomach v Small Intestine v Large Intestine v Rectum/Anus What is Peristalsis? Peristalsis is the strong wavelike muscle contractions in the organs of the digestive system that occur automatically in order to help move food along from one part to the next. What is the path food takes through your body? 3) Stomach – Food is churned and mixed with digestive juices (enzymes-Pepsinogen) and acid- hydrochloric acid) that break protein causing the bolis to becomes a thick liquid, with the consistency of a milkshake called chyme. Gastric Juices contain acids that break down food - secreted by gastric glands PEPSIN - most important digestive enzyme for breaking down food Mouth v Esophagus v Stomach v Small Intestine v Large Intestine v Rectum/Anus What is the path food takes through your body? 4) Small Intestine – Partly digested food moves from the stomach to the small intestine, where it mixes with chemicals from the pancreas and the liver. Digested food passes into the bloodstream through the villi, which line the small intestine walls, and are transported throughout the body. Villi- finger-like projections that absorbs nutrients from the food we eat, à very small one is called microvilli. Mouth v Esophagus v Stomach v Small Intestine v Large Intestine v Rectum/Anus What is the path food takes through your body? 5) Large Intestine – Materials that cannot be absorbed pass into the large intestine. The large intestine absorbs water and stores waste until it can be eliminated from the body. - Its function is to reabsorb water into the bloodstream Mouth v Esophagus v Stomach v Small Intestine v Large Intestine v Rectum/Anus What is the path food takes through your body? 6) Rectum/Anus – solid waste, called feces, is eliminated from the body through the rectum. Mouth v Esophagus v Stomach v Small Intestine v Large Intestine v Rectum/Anus Accessory Organs in Digestive System The accessory digestive organs include the liver,gallbladder and the pancreas. Food does not pass through these organs but they play important roles in digesting food. They each secret chemicals that help break food down. What’s the role of the liver? The Liver produces bile which breaks down fat. What’s the role of the gallbladder? The Gallbladder stores bile, produced by the liver, and releases it to the small intestine when it is needed. What’s the role of the pancreas? The Pancreas produces enzymes that flow into the small intestine to help neutralize stomach acid. These enzymes are mixed with food as it enters the small intestine. The Functions of the Digestive System as a Five -Stage Process A. Ingestion It is the taking in of food through the mouth. B. Propulsion The movement of food throughout the alimentary canal/digestive tract. C. Digestion The actual breakdown of food. Food may be broken down in two ways: Mechanical Digestion is the physical breakdown of food into smaller pieces and Chemical digestion is the breakdown of components of the food into simple forms that can be absorbed by the cells of the body. D. Absorption Involves the taking in of nutrients from the digested food into the cells of the body. These nutrients will be used by the cells to perform all of its functions. E. Defecation Is the excretion or release of waste materials that are not absorbed by the body. Release of wastes is through the anus. Disorders of the Digestive System GERD GERD (gastroesophageal reflux disease, or chronic acid reflux) is a condition in which acid-containing contents in your stomach persistently leak back up into your esophagus, the tube from your throat to your stomach - This backwash (acid reflux) can irritate the lining of your esophagus. - Many people experience acid reflux from time to time. HEPATITIS Hepatitis B is caused by the virus HBV. It is spread by contact with an infected person's blood, semen, or other body fluid. And, it is a sexually transmitted disease (STD). Some people never develop symptoms, others develop chronic symptoms that stay with them their whole life. Hepatitis C is caused by the virus HCV. It is spread the same way as hepatitis B, through contact with an infected person's blood, semen, or body fluid. Like hepatitis B, hepatitis C causes swelling of the liver and can cause liver damage that can lead to cancer. Most people who have hepatitis C develop a chronic infection. This may lead to a scarring of the liver, called cirrhosis. Blood banks test all donated blood for hepatitis C, greatly reducing the risk for getting the virus from blood transfusions or blood products. Crohn's disease is a type of inflammatory bowel disease (IBD). It causes inflammation of your digestive tract, which can lead to Crampy abdominal pain Fatigue Loss of appetite Pain with passing stool (tenesmus); bloody stool Persistent, watery diarrhea Weight loss Constipation IBS - Irritable Bowel Syndrome The muscles in the bowel wall may contract too forcefully or too weakly, too slowly or rapidly at certain times. STOMACH ULCERS An ulcer is an open, painful sore. Peptic ulcers affect the stomach and the upper part of the small intestine, called the duodenum. Ulcers in the stomach are also called stomach ulcers or gastric ulcers. Those in the duodenum are also called duodenal ulcers. Appendicitis Appendicitis is an inflammation of the appendix, a finger-shaped pouch that projects from your colon on the lower right side of your abdomen. DIARRHEA Diarrhea is a condition characterized by the frequent passage of loose, watery stools which is usually the result of increased activity of the large intestine. It may be caused by stress and anxiety,side effects of drugs, irritation, infections and many other factors including some diseases and conditions. The symptoms of diarrhea include stomach and bowel pain, cramping, loose or liquid tools and often change in the color of feces. Colon Cancer Colonoscopy is a screening technique to detect cancer. Colorectal cancer is cancer that occurs in the colon or rectum. Sometimes it is called colon cancer, for short. As the drawing shows, the colon is the large intestine or large bowel. CONSTIPATION Constipation occurs when bowel movements become less frequent and stools become difficult to pass. It happens most often due to changes in diet or routine, or due to inadequate intake of fiber. GASTRITIS Gastritis is an inflammation of the lining of the stomach. A person suffering from gastritis may experience loss of appetite, vomiting, nausea, and discomfort after eating. CARING FOR THE DIGESTIVE SYSTEM Your body system work together to keep your body healthy. Every system in the body depends on the digestive system to break down food into simpler forms. You can keep your digestive system healthy by: 1. HAVING A BALANCED DIET CARING FOR THE DIGESTIVE SYSTEM 2. DRINKING PLENTY OF WATER CARING FOR THE DIGESTIVE SYSTEM 3.EXERCISING REGULARLY CARING FOR THE DIGESTIVE SYSTEM 3. AVOID ALCOHOL,SMOKING, AND EXCESSIVE CAFFEINE