8 Digestive System. Anatomy and Physiology Overview

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1 8 Digestive System Gastroenterology The medical practice of gastroenterology encompasses treatment of diseases affecting the digestive system. The physician who specializes in treating disorders of the digestive system is called a gastroenterologist. Anatomy and Physiology Overview The primary function of the digestive system, also known as the gastrointestinal (GI) system, is to breakdown food, prepare it for absorption, and eliminate waste substances. The digestive system consists of a digestive tube called the GI tract or alimentary canal, which includes the esophagus, stomach, and intestines and several accessory organs, including the liver, gallbladder, and pancreas. The GI tract, extending from the oral cavity (mouth) to the anus, varies in size and structure in several distinct regions. It terminates at the anus, where solid wastes are eliminated from the body by means of defecation. Tongue Mouth (oral cavity) Food bolus Esophagus Pharynx Parotid gland Submandibular gland Sublingual gland Salivary glands Liver Gallbladder Stomach Duodenum Hepatic flexure Pancreas Jejunum Ascending colon Cecum Appendix Spleen Splenic flexure Transverse colon Descending colon Ileum Sigmoid colon Rectum Anus.(Figure 8-1 Organs of the digestive system (anterior view 1

2 2 DIGESTIVE SYSTEM WORD ELEMENTS oral cavity, esophagus, pharynx, and stomach Combining Forms ORAL CAVITY dent/o teeth dent/ist (DĔN-tĭst): specialist who diagnoses and treats diseases and disorders of the oral cavity (teeth and gums) -ist: specialist odont/o orth/odont/ist (ŏr-thō-dŏn-tĭst): dental specialist in prevention and correction of abnormally positioned or misaligned teeth orth: straight -ist: specialist gingiv/o gum(s) gingiv/itis (jĭn-jĭ-vī-tĭs): inflammation of gums gloss/o lingu/o or/o stomat/o tongue mouth hypo/gloss/al (hī-pō-glŏs-ăl): pertaining to under the tongue hypo-: under, below, deficient -al: pertaining to sub/lingu/al (sŭb-lĭng-gwăl): pertaining to under the tongue sub-: under, below -al: pertaining to or/al (OR-ăl): pertaining to the mouth -al: pertaining to stomat/o/pathy (stō-mă-tŏp-ă-thē): disease of the mouth -pathy: disease ptyal/o saliva ptyal/ism (TĪ-ă-lĭzm): condition of excessive salivation -ism: condition sial/o saliva, salivary gland sial/o/rrhea (sī-ă-lō-rē-ă): excessive flow of saliva; also called hypersalivation or ptyalism -rrhea: discharge, flow ESOPHAGUS, PHARYNX, AND STOMACH esophag/o esophagus esophag/o/scope (ē-sŏf-ă-gō-skōp): instrument for examining the esophagus -scope: instrument for examining

3 3 DIGESTIVE SYSTEM pharyng/o pharynx (throat) pharyng/o/tonsill/itis (fă-rĭng-gō-tŏn-sĭ-lī-tĭs): inflammation of the pharynx and tonsils tonsill: tonsils gastr/o stomach gastr/o/scopy (găs-trŏs-kō-pē): visual examination of the stomach -scopy: visual examination The gastroscope is a flexible, fiberoptic instrument used to inspect the interior of the stomach. pylor/o pylorus pylor/o/tomy (pī-lor-ŏt-ō-mē): incision of the pylorus (sphincter in lower portion of the stomach) -tomy: incision Pylorotomy is usually performed to remove an obstruction. Suffixes -algia -dynia pain gastr/algia (găs-trăl-jē-ă): pain in the stomach gastr: stomach gastr/o/dynia (găs-trō-dĭn-ē-ă): pain in the stomach gastr/o: stomach -emesis vomiting hyper/emesis (hī-pĕr-ĕm-ĕ-sĭs): excessive vomiting hyper-: excessive, above normal -megaly enlargement gastr/o/megaly (găs-trō-mĕg-ă-lē): enlargement of the stomach gastr/o: stomach -orexia appetite an/orexia (ăn-ō-rĕk-sē-ă): loss of appetite an-: without, not Anorexia can result from various conditions, such as adverse effects of medication as well as other physical or psychological causes. -pepsia digestion dys/pepsia (dĭs-pĕp-sē-ă): difficult or painful digestion; also called indigestion dys-: bad; painful; difficult Dyspepsia is a feeling of epigastric discomfort after eating. -phagia swallowing, eating dys/phagia (dĭs-fā-jē-ă): difficulty swallowing or eating dys-: bad; painful; difficult -rrhea discharge, flow dia/rrhea (dī-ă-rē-ă): discharge or flow of watery stools from the bowel dia-: through, across

4 4 Upper GI Tract WORD ELEMENTS SMALL INTESTINE AND COLON Combining Forms SMALL INTESTINE duoden/o enter/o jejun/o ile/o duodenum (first part of small intestine) intestine (usually small intestine) jejunum (second part of small intestine) ileum (third part of small intestine) duoden/o/scopy (dū-ŏd-ĕ-nŏs-kō-pē): visual examination of the duodenum -scopy: visual examination enter/o/pathy (ĕn-tĕr-ŏp-ă-thē): any intestinal disease -pathy: disease jejun/o/rrhaphy (jĕ-joo-nor-ă-fē): suture of the jejunum -rrhaphy: suture ile/o/stomy (ĭl-ē-ŏs-tō-mē): incision of the ileum (ileotomy) and creation of a permanent opening -stomy*: forming an opening (mouth) Ileostomy is performed following a total colectomy. The ileum is pulled out through the abdominal wall. The edges of the wall of the colon are rolled to make a mouth (stoma) that is then sutured to the abdominal wall. The patient wears a plastic pouch on the abdomen to collect feces. LARGE INTESTINE append/o appendix appendic/o append/ectomy (ăp-ĕn-dĕk-tō-mē): removal of the appendix -ectomy: excision, removal Appendectomy is performed to remove a diseased appendix that is in danger of rupturing. appendic/itis (ă-pĕn-dĭ-sī-tĭs): inflammation of the appendix *When the suffi x -stomy is used with a combining form that denotes an organ, it refers to a surgical opening to the outside of the body. (continued)

5 5 DIGESTIVE SYSTEM col/o colon col/o/stomy (kō-lŏs-tō-mē): creation of an opening between the colon and the abdominal wall -stomy: forming an opening (mouth) A colostomy creates a place for fecal matter to exit the body other than through the anus. It may be temporary or permanent. colon/o colon/o/scopy (kō-lŏn-ŏs-kō-pē): visual examination of the inner surface of the colon using a long, flexible endoscope -scopy: visual examination proct/o anus, rectum proct/o/logist (prŏk-tŏl-ō-jĭst): physician who specializes in treating disorders of the colon, rectum, and anus -logist: specialist in study of rect/o rectum rect/o/cele (RĔK-tō-sēl): herniation or protrusion of the rectum; also called proctocele -cele: hernia, swelling sigmoid/o sigmoid colon sigmoid/o/tomy (sĭg-moyd-ŏt-ō-mē): incision of sigmoid colon -tomy: incision

6 6 DIGESTIVE SYSTEM WORD ELEMENTS ACCESSORY ORGANS OF DIGESTION Word Elements Meaning Word Analysis Combining Forms cholangi/o bile vessel cholangi/ole (kō-lăn-jē-ōl): small terminal portion of the bile duct -ole: small, minute chol/e* bile, gall chol/e/lith (kō-lē-lĭth): gallstone -lith: stone, calculus cholecyst/o gallbladder cholecyst/ectomy (kō-lē-sĭs-tĕk-tō-mē): removal of gallbladder by laparoscopic or open surgery -ectomy: excision, removal Cholecystectomy can be performed by open surgery or laparoscopically (placing a tube into the abdomen). choledoch/o bile duct choledoch/o/tomy (kō-lĕd-ō-kŏt-ō-mē): incision of the common bile duct -tomy: incision hepat/o liver hepat/itis (hĕp-ă-tī-tīs): inflammation of the liver pancreat/o pancreas pancreat/o/lysis (păn-krē-ă-tŏl-ĭ-sĭs): destruction of pancreas by pancreatic enzymes -lysis: separation; destruction; loosening Suffixes -iasis abnormal condition (produced by something specified) chol/e/lith/iasis (kō-lē-lĭ-thī-ă-sĭs): presence or formation of gallstones chol/e: bile, gall lith/o: stone, calculus -megaly enlargement hepat/o/megaly (hĕp-ă-tō-mĕg-ă-lē): enlargement of the liver hepat/o: liver Hepatomegaly may be caused by infection; fatty infiltration, as in alcoholism; biliary obstruction; or malignancy. *Using the combining vowel e instead of o is an exception to the rule. Word Elements -osis Meaning abnormal condition; increase (used primarily with blood cells) Word Analysis cirrh/osis (sĭr-rō-sĭs):abnormal condition of yellowness Cirrhosis is a chronic liver disease characterized by destruction of liver cells. It eventually leads to impaired liver function and jaundice. -prandial meal post/prandial (pōst-prăn-dē-ăl): following a meal post-: after, behind