2Structures of the Digestive System The major structures of the digestive system include the oral cavity (mouth), pharynx, esophagus, stomach, small intestine, large intestine, rectum and anus.Accessory organs: liver, gallbladder, and pancreas
4Word Parts or/o = mouth pharyng/o = pharynx esophag/o = esophagus gastr/o = stomachenter/o = small intestinescol/o = large intestines (colon)
5an/o, proct/o, rect/o = anus and rectum hepat/o = livercholecyst/o = gallbladderpancreat/o = pancreas-lithiasis = presence of stones-pepsia = digestion
6The digestive system - known as the alimentary canal. The structures of the digestive system are also described as the gastrointestinal (GI) tract.(gastr/o = stomach, intestin = instestines, al = pertaining to)Let’s start with the oral cavity, or the mouth:
8The Palate Hard palate – bony anterior portion Rugae – irregular ridges or folds in the mucous membrane, covering the anterior portion of the hard palate.Soft palate – flexible posterior portion.
9The Tongue gloss/o or lingu/o = tongue; upper surface has a tough protective coveringpapillae are the ‘taste buds’underside of the tongue - highly vascular; covered with delicate tissue (easier to absorb some medications)sublingual – under the tongue.
10Terms related to the teeth: dentition – the natural teethedentulous – without teethprimary dentition = baby teeth; consists of 20 teeth.permanent dentition – 32 teeth; designed to last a lifetime.
11Let’s do a quick survey….. Everyone gets an index card and a red/green card.
12Using your cell phones, text one of each of these questions to three different people. You have 10 minutes to obtain the answers.Write the answers down and flip your card to green when you have this completed.
131. What did you have for breakfast? 2. What does the word “gingivitis” mean?3. How many times do you brush your teeth each day?
14Other structures….uvula – hangs down from the free edge of the soft palate; helps in producing sounds and speech.gingiva – gums; specialized mucous membrane that surrounds the teeth, covers the bone of dental arches, forms the lining of the cheeks.
15The Salivary GlandsThe salivary glands secrete saliva that moistens food, begins the digestive process, and cleanses the mouth.3 pairs: parotid - on face in front of and slightly lower than each ear; sublingual – under tongue: mandibular – on the floor of the mouth.
16The Pharynxthe throatcommon passageway for both respiration and digestionDuring swallowing, the epiglottis closes off the entrance to the trachea, so that food moves safely into the esophagus.
18The EsophagusA collapsible tube that leads from the pharynx to the stomachcardiac sphincter – at lower end of esophagus; is a ring-like muscle that controls the flow of food between the esophagus and the stomach; one-way.
19The Stomach Has three parts: fundus – upper, rounded part body – main portionantrum – lower part
21rugae – folds in the mucosa lining the stomach. Glands within these folds produce the gastric juices that aid in digestion and mucus that forms the protective coating of the lining of the stomach.
22The pylorus is the narrow passage connecting the stomach with the small intestine. The pyloric sphincter is the muscle ring that controls the flow from the stomach to the first part of the small intestine (the duodenum).
24Small Intestine (enter/o) Consists of three parts:Duodenum – first portionJejunum – second portionIleum – last portionThe ileocecal sphincter controls the flow from the ileum into the cecum of the large intestine.
27Large Intestine (col/o) Extends from the end of the small intestine to the anus.The waste products of digestion are processed in the large intestine and then excreted through the anus.Major parts of large intestine: cecum, colon, rectum, anus.
28The CecumA pouch on the right side of the abdomen; extends from end of the ileum to the beginning of the colon.Veriform appendix – hangs from the lower part of cecum.Appendix serves no known function in digestion; is lymphatic tissue.
32Rectum and AnusRectum – last division of the large intestine; ends at anusAnus – lower opening of digestive tract.The flow of waste through the anus is controlled by anal sphincter muscles.
33The Liver (hepat/o) Located in RUQ of abdomen Functions: removes excess glucose (blood sugar) and stores it as glycogen. When the blood sugar level is low, it converts the glycogen back to glucose and releases it for use by the body.
34The liver also destroys old RBCs, removes poisons from the blood, and manufactures some blood proteins.Bilirubin – pigment produced from the destruction of hemoglobin, is released by the liver in bile. Excess bilirubin is associated with jaundice.
35The liver secretes bile, which is a digestive juice containing enzymes that break down fat. Bile travels down the common hepatic duct to the gallbladder, where bile is stored.
36The Gallbladder (cholecyst/o) Pear-shaped sac located under the liver. It stores and concentrates bile for later use.The term cholecystic means pertaining to the gallbladder.When bile is needed, the gallbladder contracts, sending the bile through the cystic duct and into the common bile duct that carries it to the duodenum.
39The Pancreas (pancreat/o) A feather-shaped organ located posterior to the stomach.It synthesizes and secretes pancreatic juices.These juices are made up of sodium bicarbonate (to help neutralize stomach acids) and digestive enzymes.
40The pancreatic juices leave the pancreas through the pancreatic ducts that join the common bile duct just before entrance to the duodenum.
42DigestionThe process by which complex foods are broken down into nutrients in a form the body uses.Enzyme – responsible for chemical changes that break foods into simpler forms of nutrients for the body to use.
43Nutrient – a substance, usually from food, that is necessary for normal functioning of the body. Six types of nutrients: water, carbohydrates, protein, fats, vitamins, and minerals.Each type of nutrient has a specific purpose and meets a specific need that your body has.
44WaterYes, water is a nutrient. It is the most important nutrient. In fact, your body is approximately 50 to 55 percent water. Your body uses water 24 hours a day. A by-product of the energy production in your body is heat. Water regulates your body temperature by dissipating that heat. Water also carries nutrients to the cells in your body. Water does not produce energy.
45Carbohydrates are the primary source of energy for your body. Carbohydrates power every system in your body, including your brain, heart, muscles and internal organs.Carbohydrates can be simple (table sugar, corn syrup) or complex (whole grain). Simple carbohydrates enter your bloodstream very quickly. That is why you get a sugar high when you eat candy. Complex carbohydrates are processed and used more slowly.
46ProteinProtein is like the brick and mortar of your body. It is the building blocks that provide the structure for the tissues of your body. Proteins are also used to transport essential elements in your blood stream.
47Fats are our storehouses of energy Fats are our storehouses of energy. When we have excess nutrients in our body, some of it is stored as fat.The primary purpose of fat is energy production. There are two main types of fats - saturated and unsaturated.Animal fats (meat, butter, lard) are usually saturated fats and contribute to heart disease and cancer.
48Vegetable fats (olive oil, corn oil) are generally unsaturated fats and are less harmful. Some fats have been found to be helpful in preventing some cancers and heart disease. These fats called omega-3 fatty acids are found in some fish, especially cold-water fish.
49VITAMINSVitamins are essential for the regulation of many of the functions of the body.Most vitamins cannot be manufactured by the body and must be obtained from your diet. Vitamins do not produce energy.
50Minerals are compounds, obtained from your diet, that combine in several ways to form the structures of your body. For instance, calcium is a mineral that is crucial in the formation and maintenance of your bones.Minerals also help regulate body functions. Minerals do not produce energy.
51Metabolism Is the sum of anabolism and catabolism. The term “metabolism” includes all of the processes involved in the body’s use of these nutrients.
52anabolism – is the building up of body cells and substances from nutrients. catabolism – is the opposite of anabolism. It is the breaking down of body cells or substances, and they release energy and carbon dioxide.
53Terms related to the Digestive System: Borborygmus – the rumbling noise caused by the movement of gas in the intestine.Gastroenterologist - specialist who treats diseases and disorders of the stomach and intestines.
54Bruxism – involuntary grinding or clenching of the teeth; usually occurs during sleep; assoc. with stress / tension.It wears away tooth structure, damages periodontal tissues, injures the temporomandibular (TMJ) joint.
55Halitosis – bad breath. May be caused by dental diseases, or respiratory or gastric problems. Dysphagia – condition of difficult swallowing.Esophageal reflux or GERD – the upward flow of stomach acid into the esophagus.Pyrosis – heartburn. (pyro = fever or fire)
56Hiatal hernia – a protrusion of part of the stomach through the esophageal sphincter in the diaphragm. This condition may cause esophageal reflux or pyrosis.
58Peptic ulcer – a lesion of the mucous membranes of the digestive system. Usually caused by the bacterium Helicobacter pylori ( H pylori), and it may occur in the lower end of the esophagus, the stomach, or in the duodenum.
59Gastric ulcer – peptic ulcer in the stomach. Duodenal ulcer - peptic ulcer in the duodenum. Is the most common form of peptic ulcer.Perforating ulcer – involves erosion through the entire thickness of the organ wall.
60Eating disorders:Anorexia – lack or loss of appetite for food.Anorexia nervosa – refusal to maintain a minimally normal body weight and an intense fear of gaining weight. Compulsive dieting; excessive exercising.
61Bulimia – episodes of binge eating followed by self-induced vomiting or misuse of laxatives or diuretics.Obesity – excessive accumulation of fat in the body % over the established weight standards.
62Pica – persistent eating of non-nutritional substances such as clay. Eructation – belchingEmesis – vomitingHyperemesis – excessive vomiting.Hematemesis – vomiting blood
63Diverticulum – a pouch or sac occurring in the lining or wall of the intestines. Diverticulitis – inflammation of one or more diverticulum.Colorectal cancer – common form of cancer that often first shows up as polyps in the colon.
65Intussusception – telescoping of one part of the intestine into the opening of an adjacent part. This is typically found in infants and young children.Volvulus - twisting of the intestine on itself that causes an obstruction.
67Bowel – another word for intestine. Colonoscopy – the direct visual examination of the inner surface of the colon, from the rectum to the cecum.Endoscopy – the examination, using an endoscope, of the interior of the esophagus, stomach, and duodenum.
69Cirrhosis – a progressive degenerative disease of the liver, characterized by the disturbance of the structure and function of the liver. Can lead to jaundice and hepatic failure.
70Hemoccult – a test done to detect blood in the stools.
71OstomiesRemember, an ostomy is a surgical procedure to create an official opening between an organ and the body surface. This opening is called a stoma.Examples:
72gastrostomy – a new opening into the stomach gastrostomy – a new opening into the stomach. This procedure is frequently done to place a permanent feeding tube.Ileostomy – a new opening between the ileum and the abdominal wall.
73Colostomy – a new opening between the colon and the body surface Colostomy – a new opening between the colon and the body surface. The entire segment of intestine below the ostomy is usually removed and a discharge flows from the stoma. It may be temporary or permanent.It is named for the part of the colon where the stoma is.
74Enterostomy (small intestine) For example:Colostomy (colon)Enterostomy (small intestine)DuodenostomyJejunostomyIleostomy