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The Language Of The Language Of MedicineMedicine1010thth edition edition
Davi-Ellen ChabnerDavi-Ellen Chabner
Chapter 5Digestive System
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Chapter Goals
• Name the organs of the digestive system and describe their locations and functions.
• Define combining forms for organs and know the meaning of related terminology.
• Describe signs, symptoms, and disease conditions affecting the digestive system.
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Chapter 5Lesson 5.1
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Introduction
The digestive or gastrointestinal systemperforms four main functions:• ingestion• digestion• absorption• elimination
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Introduction: Ingestion and Digestion
• Ingestion—food material taken into mouth
• Digestion—food is broken down, mechanically and chemically, as it travels through the gastrointestinal tract.Digestive enzymes aid the breakdown of complex
nutrients. • Proteins → amino acids• Sugars → glucose• Fats → fatty acids or triglycerides
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Introduction:Absorption
• Digested food passes into the bloodstream through lining cells of the small intestine.
• Nutrients travel to all cells of the body.
• Cells burn nutrients to release the energy stored in food.
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Introduction:Elimination
• The body eliminates solid waste materials that cannot be absorbed into bloodstream.
• The large intestine concentrates feces. • The wastes pass out of the body through
the anus.
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Organs of the Digestive System
• The gastrointestinal tract begins with the oral cavity.
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Oral Cavity
Major parts of the oral cavity
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Oral Cavity (cont’d)
Major parts of the oral cavity
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Oral Cavity (cont’d)
Upper permanent teeth within the dental arch
→
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Oral Cavity (cont’d)
Upper permanent teeth within the dental arch
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Oral Cavity (cont’d)
Anatomy of a tooth
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Oral Cavity (cont’d)
Anatomy of a tooth
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Oral Cavity (cont’d)
Salivary glands
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Pharynx
Deglutition
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Pharynx (cont’d)
Deglutition
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Esophagus/Stomach
Parts of the stomach
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Esophagus/Stomach (cont’d)
Parts of the stomach
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The Digestive Tract
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The Digestive Tract (cont’d)
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Small IntestineVilli in the lining of the small intestine
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Large Intestine
Parts of the large intestine
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Large Intestine (cont’d)
Parts of the large intestine
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Liver, Gallbladder, and Pancreas
Parts of the liver, gallbladder, and pancreas
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Liver, Gallbladder, and Pancreas (cont’d)
Parts of the liver, gallbladder, and pancreas
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Liver, Gallbladder, and Pancreas (cont’d)
Besides producing bile, the liver:• Helps maintain normal blood glucose levels• Manufactures blood proteins necessary for
clotting• Releases bilirubin, a pigment in bile• Removes toxins and poisons from the blood
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QUICK QUIZ:
1. What happens if bilirubin cannot leave the body and remains in the bloodstream?A. GluconeogenesisB. EmulsificationC. HyperbilirubinemiaD. Glycogenolysis
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Liver, Gallbladder, and Pancreas
The pancreas and its functions
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Food Pathway through the GI Tract
Food enters through the oral cavity and exits through the anus
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Food Pathway through the GI Tract (cont’d)
Food enters through the oral cavity and exits through the anus
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QUICK QUIZ:
2. Which term is the first part of the large intestine?A. CecumB. DuodenumC. JejunumD. Pylorus
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QUICK QUIZ: (cont’d)
3. Which term means swallowing?A. MasticationB. DeglutitionC. EmulsificationD. Peristalsis
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Vocabulary
• absorption
• amino acids
• amylase
• anus
Passage of materials through the walls of the small intestine into the bloodstream
Small building blocks of proteins; released when proteins are digested
Enzyme secreted by the pancreas and salivary glands to digest starch
Terminal end or opening of the digestive tract to the outside of body
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Vocabulary (cont’d)
• appendix
• bile
• bilirubin
• bowel
Blind pouch hanging from the cecum
Digestive juice made in the liver and stored in the gallbladder; breaks up large fat globules; composed of bile pigments, cholesterol, and bile salts
Pigment released by the liver in bile
Intestine
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Vocabulary (cont’d)
• canine teeth
• cecum
• colon
• common bile duct
Pointed, dog-like teeth next to the incisors; also called cuspids or eyeteeth
First part of the large intestine
Consists of the ascending, transverse, descending, and sigmoid segments
Carries bile from the liver and gallbladder to the duodenum; also called the choledochus
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Vocabulary (cont’d)
• defecation
• deglutition
• dentin
• digestion
Elimination of feces from the digestive tract through the anus
Swallowing
Primary material found in teeth; covered by the enamel in the crown and a protective layer of cementum in the root
Breakdown of complex foods to simpler forms
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Vocabulary (cont’d)
• duodenum
• elimination
• emulsification
• enamel
First part of the small intestine; measures 12 inches longAct of removal of materials from the body
Physical process of breaking up large fat globules into smaller globules
Hard, outermost layer of a tooth
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Vocabulary (cont’d)
• enzyme
• esophagus
• fatty acids
• feces
Chemical that speeds up reactions between substances; enzyme names end in –ase
Tube connecting the throat to the stomach
Substances produced when fats are digested; a category of lipids
Solid wastes; stool
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Vocabulary (cont’d)
• gallbladder
• glucose
• glycogen
• hydrochloric acid
Small sac under the liver; stores bile
Simple sugar
Starch; glucose is stored in the form of glycogen in liver cells
Substance produced by the stomach; necessary for digestion of food
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Vocabulary (cont’d)
• ileum
• incisor
• insulin
• jejunum
Third part of the small intestine
One of four front teeth in the dental arch
Hormone produced by endocrine cells of the pancreas; transports sugar from the blood into cells and stimulates glycogen formation by the liver
Second part of the small intestine
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Vocabulary (cont’d)
• lipase
• liver
• lower esophageal sphincter (LES)
Pancreatic enzyme needed to digest fats
Large organ located in the RUQ of the abdomen; secretes bile; stores sugar, iron, and vitamins; produces blood proteins; destroys worn-out RBCs; filters out toxins; normal adult liver weighs about 2 ½ to 3 pounds
Ring of muscles between the esophagus and stomach; cardiac sphincter
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Vocabulary (cont’d)
• mastication
• molar teeth
• palate
• pancreas
Chewing
Sixth, seventh, and eighth teeth from the middle on either side of the dental arch
Roof of the mouth
Organ under the stomach; produces insulin and enzymes
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Vocabulary (cont’d)
• papillae (singular: papilla)
• parotid gland
• peristalsis
• pharynx
Small, nipple-like elevations on the tongue
Salivary gland within the cheek, just anterior to the ear
Rhythmic contractions of the tubular organs
Throat, the common passageway for food from the mouth and for air from the nose
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Vocabulary (cont’d)
• portal vein
• protease
• pulp
• pyloric sphincter
Large vein bringing blood to the liver from the intestines
Enzyme that digests protein
Soft tissue within a tooth, containing nerves and blood vessels
Ring of muscle at the end of the stomach, near the duodenum; opens when a wave of peristalsis passes over it
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Vocabulary (cont’d)
• pylorus
• rectum
• rugae
• saliva
Distal region of the stomach, opening to the duodenum
Last section of the large intestine, connecting the end of the colon and the anus
Ridges on the hard palate and the wall of the stomach
Digestive juice produced by salivary glands; contains the enzyme amylase
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Vocabulary (cont’d)
• salivary glands
• sigmoid colon
• sphincter
• stomach
Parotid, sublingual, and submandibular glands
Fourth and last, S-shaped segment of the colon, just before the rectum; empties into the rectum
Circular ring of muscle that constricts a passage or closes a natural opening
Muscular organ that receives food from the esophagus
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Vocabulary (cont’d)
• triglycerides
• uvula
• villi (singular: villus)
Fat molecules composed of three parts fatty acids and one part glycerol; subgroup of lipids
Soft tissue hanging from the middle of the soft palate
Microscopic projections in the wall of the small intestine that absorb nutrients into the bloodstream
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Terminology – Combining FormsParts of the Body
• an/o• append/o, appendic/o• bucc/o• cec/o• celi/o• cheil/o• cholecyst/o• choledoch/o
anusappendixcheekcecumbelly,abdomenlipgallbladdercommon bile duct
Combining FormCombining Form MeaningMeaning
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Terminology – Combining FormsParts of the Body (cont’d)
• col/o colon• colon/o colon• dent/i tooth• duoden/o duodenum• enter/o intestines, usually small intestine• esophag/o esophagus• faci/o face• gastr/o stomach• gingiv/o gums
Combining FormCombining Form MeaningMeaning
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Terminology – Combining FormsParts of the Body (cont’d)
• gloss/o tongue• hepat/o liver• ile/o ileum• jejun/o jejunum• labi/o lip• lapar/o abdomen• lingu/o tongue• mandibul/o lower jaw, mandible• odont/o tooth
Combining FormCombining Form MeaningMeaning
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Terminology – Combining FormsParts of the Body (cont’d)
• or/o mouth• palat/o palate• pancreat/o pancreas• peritone/o peritoneum• pharyng/o throat• proct/o anus and rectum• pylor/o pyloric sphincter• rect/o rectum• sialaden/o salivary gland
Combining FormCombining Form MeaningMeaning
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Terminology – Combining FormsParts of the Body (cont’d)
• sigmoid/o sigmoid colon• stomat/o mouth• uvul/o uvula
Combining FormCombining Form MeaningMeaning
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Terminology – Combining FormsSubstances
• amyl/o starch• bil/i gall, bile• bilirubin/obilirubin (bile pigment)• chol/e gall or bile• chlorhydr/o hydrochloric acid• gluc/o sugar• glyc/o sugar
Combining FormCombining Form MeaningMeaning
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Terminology – Combining FormsSubstances (cont’d)
• glycogen/o glycogen, animal starch• lip/o fat• lith/o stone• prote/o protein• py/o pus• sial/o saliva, salivary• steat/o fat
Combining FormCombining Form MeaningMeaning
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Terminology – Suffixes
• -ase enzyme• -chezia defecation, elimination of
wastes• -iasis abnormal condition• -prandial meal
SuffixSuffix MeaningMeaning
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Combining Forms, Suffixes, and Terminology (cont’d)
Three types of anastomoses
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QUICK QUIZ:
4. Which term means inflammation of the lip?A. CholecystitisB. CeliacC. AppendicitisD. Cheilitis
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Chapter 5Lesson 5.2
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Pathology of the Digestive System
Signs and symptoms• Anorexia – lack of appetite• Ascites – abnormal accumulation of fluid in
the abdomen• Borborygmus (plural: borborygmi) – rumbling
or gurgling noise produced by the movement of gas, fluid, or both in the GI tract
• Constipation – difficulty in passing stools• Diarrhea – frequent passage of loose, watery
stools
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Pathology of the Digestive System (cont’d)
• Dysphagia – difficulty in swallowing• Eructation – gas expelled from the stomach
through the mouth• Flatus – gas expelled through the anus• Hematochezia – passage of fresh, bright red
blood from the rectum• Jaundice (icterus) – yellow-orange coloration
of the skin and whites of the eyes caused by high levels of bilirubin in the blood
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Pathology of the Digestive System (cont’d)
• Melena – black, tarry stools; feces containing digested blood
• Nausea – unpleasant sensation in the stomach associated with a tendency to vomit
• Steatorrhea – fat in the feces; frothy, foul-smelling fecal matter
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Pathologic ConditionsOral Cavity and Teeth
• Aphthous stomatitis – inflammation of the mouth with small, painful ulcers
• Dental caries – tooth decay
• Herpetic stomatitis – inflammation of the mouth by infection with the herpes virus
• Oral leukoplakia – white plaques or patches
• Periodontal disease – inflammation and degeneration of the gums, teeth and surrounding bone
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Pathologic ConditionsUpper Gastrointestinal Tract
• Achalasia – failure of the lower esophagus sphincter (LES) muscle to relax
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Pathologic ConditionsUpper Gastrointestinal Tract
• Esophageal cancer – malignant tumor of the esophagus
• Esophageal varices – swollen, varicose veins at the lower end of the esophagus
• Gastric carcinoma – malignant tumor of the
stomach
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Pathologic ConditionsUpper Gastrointestinal Tract
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Pathologic ConditionsUpper Gastrointestinal Tract (cont’d)
• Gastroesophageal reflux disease (GERD) – solids and fluids return to the mouth from the stomach
• Peptic ulcer – open sore or lesion of the mucous membrane of the stomach or duodenum
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Pathologic ConditionsUpper Gastrointestinal Tract (cont’d)
• Hernia – protrusion of an organ or part through the muscle normally containing it
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Pathologic ConditionsLower Gastrointestinal Tract
Small and Large Intestines
• Anal fistula – abnormal tube-like passageway near the anus
• Colonic polyposis – polyps protrude from the mucous membrane of the colon
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Pathologic ConditionsLower Gastrointestinal Tract
Small and Large Intestines (cont’d)
• Colorectal cancer – adenocarcinoma of the colon or rectum or both
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Pathologic ConditionsLower Gastrointestinal Tract
Small and Large Intestines (cont’d)• Crohn disease – chronic inflammation of the
intestinal tract• Diverticulosis – abnormal side pockets
(outpouchings) in the intestinal wall
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Pathologic ConditionsLower Gastrointestinal Tract
Small and Large Intestines (cont’d)
• Dysentery – painful, inflamed intestines• Hemorrhoids – swollen, twisted, varicose
veins in the rectal region• Ileus – failure of peristalsis with resulting
obstruction of the intestines• Inflammatory bowel disease (IBD) –
inflammation of the colon and small intestine
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Pathologic ConditionsLower Gastrointestinal Tract
Small and Large Intestines (cont’d)• Intussusception – telescoping of the
intestines• IBS – irritable bowel syndrome – group of
gastrointestinal symptoms associated with stress and tension
• Ulcerative colitis – chronic inflammation of the colon with the presence of ulcers
• Volvulus – twisting of the intestines on itself
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Pathologic Conditions Liver, Gallbladder, and Pancreas• Cirrhosis – chronic degenerative disease of the
liver• Pancreatic cancer – malignant tumor of the
pancreas• Pancreatitis – inflammation of the pancreas• Viral hepatitis – inflammation of the liver
caused by a virus
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Pathologic Conditions Liver Gallbladder, and Pancreas (cont’d)
• Cholelithiasis – gallstones in the gallbladder