Chapter 11 Digestive System

Objective 1: Identify organs and structures of the digestive system. Chapter 11 Objective 1: Identify organs and structures of the digestive system.

Digestive System The digestive tract, also known as the alimentary canal or the gastrointestinal tract, abbreviated as GI tract, is a long continuous tube comprising the mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus. Accessory organs are the salivary glands, liver, bile ducts, gallbladder, and pancreas. What is the term that describes the involuntary wavelike movements that propel food along the digestive tract? Where does peristalsis begin?

Functions of the Digestive System Functions of the digestive tract are ingestion, the taking of nutrients though the mouth; digestion, the mechanical and chemical break down of food for use by body cells; absorption, the transfer of digested food from the small intestine to the blood steam; and elimination, the removal of solid waste from the body. What differentiates digestive organs from accessory organs? Explain their respective roles in the digestive process.

Organs of the Digestive System The digestive system is also known as the alimentary canal, the gastrointestinal tract, or is abbreviated as the GI tract.

Organs of the Digestive Tract mouth: opening through which food passes into the body; breaks food into small particles by mastication and mixing with saliva – palate: separates the nasal cavity from the oral cavity – soft palate: posterior portion (not supported by bone) – hard palate: anterior portion (supported by bone) – uvula: soft V-shaped structure that extends from the soft palate; directs food into the throat What is mastication? Where does digestion begin?

Organs of the Digestive Tract (cont’d) tongue: consists mostly of skeletal muscle; it provides movement of food for mastication, directs food to the pharynx for swallowing, and is a major organ for taste and speech pharynx (throat): performs the swallowing action that passes food from the mouth into the esophagus Discuss the roles of these digestive tract organs.

Organs of the Digestive Tract (cont’d) esophagus: 10-inch tube that is a passageway for food, extending from the pharynx to the stomach – peristalsis, involuntary wavelike movements that propel food along the digestive tract; begins in the esophagus Discuss peristalsis.

Organs of the Digestive Tract (cont’d) stomach: J-shaped sac that mixes and stores food; container for food small intestine: 20-foot tube extending from the pyloric sphincter to the large intestine What is the pyloric sphincter and what is its function?

Organs of the Digestive Tract (cont’d) large intestine: approx. 5 feet tube that extends from the ileum to the anus; absorption of water and transit of the solid waste products of digestion take place in the large intestine Duodenum is derived from the Latin duodeni, meaning 12 each, a reference to its length. It was named in 240 BC by a Greek physician. Jejunum is derived from the Latin jejunus, meaning empty; it was so named because the early anatomists always found it empty. Ileum is derived from the Greek eilein, meaning to roll, a reference to the peristaltic waves that move food along the digestive tract. This term was first used in the early part of the seventeenth century.

Accessory Organs salivary glands: produce saliva, which flows into the mouth to begin the digestion process liver: produces bile, which is necessary for the digestion of fats bile ducts: passageways that carry bile: Describe the roles of these organs in the digestive process. The liver, bile ducts, and gallbladder comprise the biliary system. What is the function of the biliary system? Answer: creates, transports, stores, and releases bile into the small intestine to facilitate the absorption of fat.

Accessory Organs (cont’d) gallbladder: small, saclike structure that stores bile produced by the liver pancreas: produces pancreatic juice, which helps digest all types of food and secretes insulin for carbohydrate metabolism What are the islets of Langerhans and where are they located? Bile is produced in the liver and stored in the gallbladder.

Other Structures peritoneum: serous sac lining of the abdominal and pelvic cavities appendix: small pouch, which has no known function, attached to the cecum abdomen: portion of the body between the thorax and the pelvis Identify the relationship of these structures to the anatomy of the digestive system. What is the purpose of the appendix?

Review Question In choledocholithiasis, which is the word root that means stone? doch lith chol Answer: b) lith Choledoch/o means common bile duct.

Chapter 11 Objective 2: Define and spell word parts related to the digestive system.

Combining Forms of the Digestive Tract an/o antr/o cec/o col/o, colon/o duoden/o enter/o esophag/o gastr/o ile/o jejun/o or/o, stomat/o proct/o, rect/o sigmoid/o Discuss the meanings of these combining forms and the anatomical structures to which they refer. col/o and colon/o denote the large intestine. enter/o denotes the small intestine.

Combining Forms of the Accessory Organs/Combining Forms Commonly Used with Digestive System Terms abdomin/o, celi/o, lapar/o append/o, appendic/o cheil/o cholangi/o chol/e choledoch/o diverticul/o gingiv/o gloss/o, lingu/o hepat/o herni/o palat/o pancreat/o peritone/o polyp/o pylor/o sial/o steat/o uvul/o Discuss the meanings of these combining forms and the anatomical structures to which they refer. Ask students to provide examples of medical terms using append and appendic (appendectomy - appendicitis). Ask students to provide examples of medical terms using gloss and lingu (glossorrhaphy – sublingual).

Prefix and Suffix Prefix Suffix hemi- -pepsia A common prefix and suffix used in language related to the digestive system: hemi- = half and -pepsia = digestion. What is dyspepsia?

Chapter 11 Objective 3: Define, pronounce, and spell disease and disorder terms related to the digestive system.

Disease and Disorder Terms Built from Word Parts appendicitis (animation on Student Evolve site) cholangioma cholecystitis (animation on Student Evolve site) choledocholithiasis cholelithiasis colitis diverticulitis (animation on Student Evolve site) diverticulosis esophagitis gastritis gastroenteritis gastroenterocolitis gingivitis glossitis Ask students to pronounce and define the disease and disorder terms.

Disease and Disorder Terms Built from Word Parts (cont’d) hepatitis hepatoma palatitis pancreatitis peritonitis (animation on Student Evolve site) polyposis proctoptosis rectocele sialolith steatohepatitis uvulitis Ask students to pronounce and define the disease and disorder terms. Polyposis presents a high potential for malignancy. Steatohepatitis is often caused by alcohol abuse and obesity, and over time may cause cirrhosis. NASH or nonalcoholic steatohepatitis may occur in nonalcoholic patients who are obese and/or suffer from type 2 diabetes mellitus.

Review Question Which is inflammation of a structure of the mouth? proctoptosis uvulitis esophagitis Answer: B) uvulitis Ask students to pronounce and define proctoptosis and esophagitis.

Chapter 11 Objective 6: Define, pronounce, and spell complementary terms related to the digestive system.

Complementary Terms Built from Word Parts abdominal anal aphagia celiac colorectal duodenal dyspepsia dysphagia enteropathy esophageal gastric gastroenterologist gastroenterology gastromalacia hepatomegaly ileocecal Ask students to pronounce and define the complementary terms.

Complementary Terms Built from Word Parts (cont’d) nasogastric (animation on Student Evolve site) oral pancreatic peritoneal proctologist proctology rectal steatorrhea steatosis stomatitis stomatogastric sublingual Ask students to pronounce and define the listed terms. How would a medication ordered to be taken sublingually be taken?

Chapter 11 Objective 8: Interpret, read, and comprehend medical language in simulated medical statements, documents, and electronic health records.

Radiology Report ENCOUNTER DATE: 2/17/20XX EXAMINATION: Abdominal Ultrasound HISTORY: Nausea, fatigue, and jaundice. FINDINGS: Multiple scans of the upper abdomen show no focal hepatic lesions. There are numerous small shadowing calculi within the gallbladder. The gallbladder wall is not thickened, there is no pericholecystic fluid collection. The common bile duct is normal in caliber, measuring 4 mm in maximum diameter. No calculi are seen within the common bile duct. The spleen is not enlarged. No focal abnormality is identified within the pancreas. IMPRESSION: Cholelithiasis. No associated biliary dilatation. The upper abdominal sonogram is otherwise normal. This is an example of how medical terms are used in a medical report. Ask students to define the underlined terms.