Ch. 7 Digestive System - Lecture notes Ch. 7 PDF

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Medical Terminology for Health Care Professionals, 9th ed....

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Ch. 7 Digestive System Anatomy and Physiology  The primary organs of the digestive system are the mouth, pharynx, esophagus, stomach, small intestine, and large intestine.  The accessory organs of the digestive system are the salivary glands, liver, gallbladder, and pancreas  The 3 main functions of the digestive system are digestion, absorption, and elimination o Digestion is the process by which food is changed in the mouth, stomach, and intestines by chemical, mechanical, and enzymatic action, so that the body can absorb it o Absorption is the process by which nutrient material is taken into the bloodstream or lymph and travels to all cells of the body o Elimination is the process whereby the solid waste (end) products of digestion are excreted.  Mouth (oral cavity)- mechanically breaks food apart by the action of the teeth; moistens and lubricates food with saliva; food formed into a bolus, a soft mass of chewed food ready to be swallowed  Teeth- used in mastication (chewing)  Salivary glands- secrete saliva to moisten and lubricate food  Pharynx- common passageway for both respiration and digestion; muscular constrictions move the swallowed bolus into the esophagus  Esophagus- moves the bolus by peristalsis (wavelike contractions) down the esophagus into the stomach  Stomach- reduces food to a digestible state; converts the food to a semiliquid state called chyme (mixture of partly digested food and digestive secretions)  Small intestine- digestion and absorption take place chiefly in the small intestine; nutrients are absorbed and transferred to body cells by the circulatory system  Large intestine- reabsorbs water from the fecal material, stores, and then eliminates waste from the body via the rectum and anus  Liver- changes glucose to glycogen and stores it until needed; changes glycogen back to glucose; desaturates fats; assists in protein catabolism (the metabolic breaking-down of complex substances into more basic elements); manufactures bile, fibrinogen, prothrom-bin, heparin, and blood proteins; stores vitamin; produces heat; and detoxifies toxins  Gallbladder- stores and concentrates bile that has been produced by the liver  Pancreas- secretes pancreatic juice into the small intestine, contains cells that produce digestive enzymes, produces the hormones insulin and glucagon Mouth 

The gingivae (gums) surround the necks of the teeth.

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The free portion of the tongue is connected to the underlying epithelium by a thin fold of mucous membrane, the lingual frenulum, which prevents extreme movement of the tongue The tongue is made of skeletal muscle and is covered with mucous membrane The tongue can be divided into a blunt rear portion called the root, a pointed tip, and a central body. Located on the surface of the tongue are papillae (elevations) and taste buds (sweet, sour, salty, bitter, and savory)

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Deciduous teeth (20)- the temporary teeth of the primary dentition, includes 8 incisors, 4 canines (cuspids), and 8 molars. Also referred to as milk teeth or baby teeth. Secondary dentition teeth (32)- includes 8 incisors, 4 canines, 8 premolars, and 12 molars which are permanent Incisors- they present a sharp cutting edge, adapted for biting into food. They form the 4 front teeth in each dental arch. The canine or cuspid teeth are larger and stronger than the incisors. Their roots sink deeply into the bones and cause well-marked prominences upon the surface The premolars or bicuspid teeth are situated lateral to and behind the canine teeth. The molar teeth are the largest of the permanent set, and their broad crowns are adapted for grinding and pounding food. Each tooth consists of 3 main portions: the crown, projecting above the gum; the root, embedded in the alveolus; and the neck, the constricted portion between the crown and root. Pulp cavity- receives blood vessels and nerves from the root canal, a narrow tunnel located at the root, or base, of the tooth. Blood vessels and nerves enter the root canal through an opening called the apical foramen to supply the pulp cavity. The root of each tooth sits in a bony socket called an alveolus. Collagen fibers of the periodontal ligament extend from the dentin of the root to the bone of the alveolus, creating a strong articulation known as gomphosis, which binds the teeth to bony sockets in the maxillary bone and mandible. A layer of cementum (a thin layer of bone) covers the dentin of the root, providing protection and firmly anchoring the periodontal ligament The solid portion of the tooth consists of the dentin, which forms the bulk of the tooth; the enamel, which covers the exposed part of the crown and is the hardest and more compact part of a tooth; and the cementum, which is deposited on the surface of the root Gingival sulcus- a shallow groove that surrounds the neck of each tooth

Pharynx  Pharynx (throat)- a chamber that extends between the internal nares and the entrance to the larynx and esophagus  Its 3 subdivisions are the nasopharynx, oropharynx, and the laryngopharynx

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Nasopharynx- located above the soft palate Oropharynx- the middle portion that lies between the soft palate and the hyoid bone and has an opening to the oral cavity Laryngopharynx- the lowest portion located below the hyoid bone and opens inferiorly to the larynx anteriorly and the esophagus posteriorly Larynx- voice box that begins in the pharynx Epiglottis- a flap of tissue that blocks the opening of the larynx that prevents food from entering the airway leading to the trachea (windpipe)

Esophagus  Esophagus- muscular tube about 10 inches long that leads from the pharynx to the stomach  At the junction with the stomach is the lower esophageal sphincter (LES) or cardiac sphincter  Food is carried along the esophagus by a series of wavelike muscular contractions called peristalsis Stomach  The stomach is a muscular, distensible saclike portion of the alimentary canal between the esophagus and duodenum  The upper region of the stomach is called the fundus  The main portion of the stomach is called the body  The lower region of the stomach is called the antrum  There are folds in the mucous membrane lining the stomach called rugae that stretch when the stomach fills with food and contain glands that produce digestive juices  Hydrochloric acid and gastric juices help convert food to a semiliquid state called chyme, which is passed at intervals through a valve called the pyloric sphincter into the small intestine Small Intestine  The small intestine is about 21 feet long and 1 inch in diameter. It extends from the pyloric sphincter at the base of the stomach to the entrance of the large intestine  The small intestine is divided into 3 parts: the duodenum, the jejunum, and the ileum  The duodenum is the first 12 inches just beyond the stomach  The jejunum is the next 8 feet  The ileum is the remaining 12 feet of the tube Large Intestine  The large intestine is about 5 feet long and 2 1/2 inches in diameter  The large intestine is divided into the cecum, the colon, the rectum, and the anal canal  The cecum is a pouchlike structure forming the beginning of the large intestine. It is about 3 inches long and has the appendix attached to it.  The colon makes up the bulk of the large intestine and is divided into the ascending colon, the transverse colon, the descending colon, and the sigmoid colon Accessory Organs

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The salivary glands, liver, gallbladder, and pancreas are not actually part of the digestive tube, but they are closely related to the digestive process Salivary Glands  The salivary glands secrete saliva in response to the sight, smell, taste, or mental image of food.  The various salivary glands are the parotid, located on either side of the face slightly below the ear; the submandibular, located in the floor of the mouth; and the sublingual, located below the tongue Liver  Liver- the largest glandular organ in the body that is located in the upper right part of the abdomen  The liver plays an essential role in the normal metabolism of carbohydrates, fats, and proteins  In protein metabolism, the liver acts as a storage place and assists in both protein catabolism and anabolism.  Catabolism- metabolic breaking-down of complex substances into more basic elements  Anabolism- building-up of the body substances in the constructive phase of metabolism  The liver manufactures the following important substances  Bile- digestive juice important in fat emulsification (the breakdown of large fat globules into smaller particles)  Fibrinogen and prothrombin- coagulants essential for blood clotting  Heparin- anticoagulant that helps to prevent the clotting of blood  Blood proteins- albumin, gamma globulin Gallbladder  Gallbladder (GB)- a small pear-shaped sac under the liver. It stores bile, which is produced by the liver, and then concentrates it for future use  Bile leaving the gallbladder is 6-10 times more concentrated as that which comes to it from the liver. Concentration is accomplished by removal of water Pancreas  Pancreas- a large, elongated gland situated behind the stomach that secretes pancreatic juice into the small intestine  The pancreas is 6-9 inches long and contains cells that produce digestive enzymes Combining Forms  absorpt/o- to take in  aden/o- gland  amyl/o- starch  anabol/o- building-up  append/o- appendix  appendic/o- appendix  bil/i- gall, bile  bucc/o- cheek  catabol/o- casting-down  celi/o- abdomen, belly

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cheil/o- lip chol/e- gall, bile choledoch/o- common bile duct cirrh/o- orange-yellow col/o- colon colon/o- colon cyst/o- bladder dent/o- tooth diverticul/o- diverticula duoden/o- duodenum enter/o- intestine esophage/o, esophag/o- esophagus gastr/o- stomach gingiv/o- gums gloss/o- tongue glyc/o- sweet, sugar halit/o- breath hemat/o- blood hemorrh/o- vein liable to bleed hepat/o- liver herni/o- hernia ile/o- ileum labi/o- lip lapar/o- abdomen lingu/o- tongue mes/o- middle odont/o- tooth pancreat/o- pancreas pept/o- to digest pharyng/e, pharyng/o- pharynx pil/o- hair prand/i- meal proct/o- anus and rectum pylor/o- pylorus, gatekeeper rect/o- rectum sial/o- saliva, salivary sigmoid/o- sigmoid splen/o- spleen stomat/o- mouth verm/i- worm -stomy- new opening

Word Roots  constipat- to press together

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eme- to vomit laxat- to loosen log- study masticat- to chew nid- nest paralyt- to disable, paralysis volvul- to toll

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Absorption- process by which nutrient material is transferred from the gastrointestinal tract into the bloodstream or lymph  absorpt- to take in  -ion- process Amylase- enzyme that breaks down starch. Ptyalin is a salivary amylase and amylopsin is a pancreatic amylase  amyl- starch  -ase- enzyme Anabolism- building-up of body substances in the constructive phase of metabolism  anabol- building-up  -ism- condition Anorexia- lack of appetite; decreased desire for food  an- lack of  -orexia- appetite Appendectomy- surgical excision of the appendix. Surgical removal of the appendix.  append- appendix  -ectomy- surgical excision Appendicitis- inflammation of the appendix. A point of tenderness in acute appendicitis is known as McBurney point, located on the right side of the abdomen, 1-2 inches above the anterosuperior spine of the ilium on a line between the ilium and the umbilicus  appendic- appendix  -itis- inflammation Ascites- significant accumulation of serous fluid in the peritoneal cavity Biliary- pertaining to the bile  bil/i- gall, bile  -ary- pertaining to Bilirubin- orange-colored bile pigment produced by the separation of hemoglobin into parts that are excreted by the liver cells Black hairy tongue- condition in which the tongue is covered by hairlike papillae entangled with threads produced by Aspergillus niger or Candida albicans fungi or by bacteria. This unusual condition could be caused by poor oral hygiene and/or overgrowth of fungi due to antibiotic therapy Bowel- intestine; the long tube in the body that stores and then eliminates waste out of the body Buccal- literally means pertaining to the cheek; relating to the cheek or mouth

bucc- cheek -al- pertaining to Catabolism- literally a casting-down; in metabolism a breaking-down of complex substances into more basic elements  catabol- casting-down  -ism- condition Celiac- pertaining to the abdomen  celi- abdomen, belly  -ac- pertaining to Cheilosis- abnormal condition of the lip as seen in riboflavin and other B-complex deficiencies  cheil- lip  -osis- condition Cholecystectomy- surgical excision of the gallbladder. With laparoscopic cholecystectomy, the gallbladder is removed through a small incision near the navel. Gallstones (cholelithiasis) are usually present in the removed gallbladder  chol/e- gall, bile  cyst- bladder  -ectomy- surgical excision Cholecystitis- inflammation of the gallbladder  chol/e- gall, bile  cyst- bladder  -itis- inflammation Choledochotomy- surgical incision of the common bile duct  choledoch/o- common bile duct  -tomy- incision Cirrhosis- chronic degenerative liver disease characterizes by changes in the lobes; parenchymal cells and the lobules are infiltrated with fat  cirrh- orange-yellow  -osis- condition Colectomy- surgical excision of part of the colon  colo- colon  -ectomy- surgical excision Colon cancer- malignancy of the colon; sometimes called colorectal cancer Colonoscope- thin, lighted, flexible instrument that is used to view the interior of the colon during a colonoscopy  colon/o- colon  -scope- instrument for examining Colonoscopy- visual examination of the colon via the colonoscope  colon/o- colon  -scopy- to view, examine, visual examination Colostomy- a surgical procedure that brings one end of the large intestine out through an opening (stoma) made in the abdominal wall. Stool moving through the intestine drains through the stoma into a bag attached to the abdomen. A colostomy can be  

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permanent or temporary. The most common types are transverse, descending, and sigmoid, so named due to the site of the disorder and the location of the stoma  col/o- colon  -stomy- new opening Constipation- infrequent passage of unduly hard and dry feces; difficult defecation  constipat- to press together  -ion- process Crohn Disease- chronic autoimmune disease that can affect any part of the gastrointestinal tract but most commonly occurs in the ileum Dentalgia- pain the tooth; toothache  dent- tooth  -algia- pain, ache Dentition- type, number, and arrangement of teeth in the dental arch Diarrhea- frequent passage of unformed watery stool  dia- through  -rrhea- flow Diverticulitis- inflammation of the diverticula (pouches in the walls of an organ) in the colon. Symptoms include pain, fever, chills, cramping, bloating, constipation, and diarrhea. Treatment depends on the severity of the condition  diverticul- diverticula  -itis- inflammation Duodenal- pertaining to the duodenum, the first part of the small intestine  duoden- duodenum  -al- pertaining to Dysentery- an intestinal disease characterizes by inflammation of the mucous membrane  dys- difficult  enter- intestine  -y- pertaining to Dyspepsia- difficult in digestion; indigestion  dys- difficult  -pepsia- to digest, digestion Dysphagia- difficulty swallowing  dys- difficult  -phagia- to eat, to swallow Emesis- vomiting  eme- to vomit  -sis- condition Enteric- pertaining to the small intestine  enter- small intestine  -ic- pertaining to Enteritis- inflammation of the small intestine  enter- small intestine  -itis- inflammation

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Enzyme- protein substance capable of causing rapid chemical changes in other substances without being changed itself Epigastric- pertaining to the region above the stomach  epi- above  gastr- stomach  -ic- pertaining to Esophageal- pertaining to the esophagus  esophage- esophagus  -al- pertaining to Feces- body waste discharged from the bowel by way of the anus; also called bowel movement (BM), stool, excreta Flatus- literally means a blowing in Latin; the expelling of gas from the anus. The average person passes 400-1200 mL of gas each day Gastrectomy- surgical excision of a part of or the whole stomach  gastr- stomach  -ectomy- surgical excision Gastric- pertaining to the stomach  gastr- stomach  -ic- pertaining to Gastroenteritis- inflammation of the stomach and intestine  gastr/o- stomach  enter- intestine  -itis- inflammation Gastroenterologist- physician who specialized in the stomach and intestine  gastr/o- stomach  enter/o- intestine  log- study  -ist- one who specializes Gastroenterology- study of the stomach and intestine  gastr/o- stomach  enter/o- intestine  -logy- study of Gastroesophageal- pertaining to the stomach and esophagus  gastr/o- stomach  esophage- esophagus  -al- pertaining to Gastroesophageal reflux disease (GERD)- condition that occurs when the muscle between the esophagus and the stomach, the lower esophageal sphincter, is weak or relaxes inappropriately, allowing the stomach's contents to back up (reflux) into the esophagus. Symptoms include heartburn, belching, and regurgitation of food Gavage- to feed liquid or semiliquid food via a tube (stomach or nasogastric [NG]) Gingivitis- inflammation of the gums  gingiv- gums  -itis- inflammation

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Glossectomy- partial or complete surgical excision of the tongue  gloss- tongue  -ectomy- excision Glycogenesis- formation of glycogen from glucose  glyc/o- sweet, sugar  -genesis- formation, produce Halitosis- bad breath  halit- breath  -osis- condition Hematemesis- vomiting of blood  hemat- blood  -emesis- vomiting Hemorrhoid- mass of dilated, tortuous veins in the anorectum; can be internal or external  hemorrh- vein liable to bleed  -oid- resemble Hepatitis- inflammation of the liver  hepat- liver  -itis- inflammation Hernia- abnormal protrusion of an organ or a part of an organ through the wall of the body cavity that normally contains it. A hiatal hernia occurs when the upper part of the stomach moved up into the chest through a small opening in the diaphragm. An umbilical hernia occurs when part of the intestine protrudes through an opening in the abdominal muscles. Umbilical hernias are most common in infants, but they can affect adults as well. In an infant, an umbilical hernia may be especially evident when the infant cries, causing the baby's naval to protrude. An inguinal hernia occurs when a loop of intestine enters the inguinal canal (groin area), a tubular passage through the lower layers of the abdominal wall Herniorrhaphy- surgical repair of a hernia  herni/o- hernia  -rrahpy- suture Hyperemesis- excessive vomiting  hyper- excessive, above  -emesis- vomiting Hypogastric- pertaining to below the stomach  hypo- deficient  gastr- below stomach  -ic- pertaining to Ileostomy- the surgical creation of a new opening through the abdominal wall into the ileum  ile/o- ileum  -stomy- new opening Inflammatory bowel disease (IBD)- broad term that describes conditions with chronic or recurring abnormal immune response and inflammation of the gastrointestinal tract.

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