1. Chapter 5
Objectives
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.

2. Digestive System
Chapter 5
Pages 139 – 186

3. Page 140
Introduction
The digestive or gastrointestinal system performs four main functions. They are:
Ingestion
Digestion
Absorption
Elimination
The digestive or gastrointestinal tract begins with the mouth, where food enters, and ends with the anus, where solid waste material leaves the body.
The four functions of the system are ingestion, digestion, absorption, and elimination.
First, complex food material taken into the mouth is ingested.
Second, it is digested, or broken down, mechanically and chemically, as it travels through the gastrointestinal tract.
Digestive enzymes speed up chemical reactions and aid the breakdown (digestion) of complex nutrients.
Complex proteins are digested to simpler amino acids; complicated sugars are reduced to simple sugars, such as glucose; and large fat or lipid molecules are broken down to simpler substances such as fatty acids and triglycerides (three parts fatty acids and one part glycerol).
Digestion occurs in the mouth, stomach, and small intestine.
Third, through absorption, nutrients from digested food pass through the lining cells or epithelium of the small intestine and into the bloodstream. (water is absorbed in the large intestine)
Nutrients then travel to all cells of the body.
Cells then break down nutrients in the presence of oxygen to release energy.
Cells also use amino acid nutrients to build up large protein molecules needed for growth and development.
In addition, fat molecules are absorbed into lymphatic vessels from the intestine.
The fourth function of the digestive system is elimination of the solid waste materials that cannot be absorbed into the bloodstream.
The large intestine concentrates these solid wastes, called feces, and the wastes finally pass out of the body through the anus.

4. Page 140
Oral Cavity
The gastrointestinal tract begins with the ORAL CAVITY. 
Oral means pertaining to the mouth (or/o).
The CHEEKS form the walls of the oval-shaped oral cavity, and the LIPS surround the opening to the cavity.
The HARD PALATE forms the anterior portion of the roof of the mouth, and the muscular SOFT PALATE lies posterior to it. 
RUGAE are irregular ridges in the mucous membrane covering the anterior portion of the hard palate.
The UVULA, a small soft tissue projection, hangs from the soft palate.
It aids production of sounds and speech.
The TONGUE extends across the floor of the oral cavity, and muscles attach it to the lower jawbone.
It moves food around during MASTICATION (chewing) and DEGLUTITION (swallowing). 
PAPILLAE, small raised areas on the tongue, contain taste buds that are sensitive to the chemical nature of foods and allow discrimination of different tastes as food moves across the tongue.

5. Tonsils and Salivary Glands
Page 140
Tonsils and Salivary Glands
The TONSILS, masses of lymphatic tissue located in depressions of the mucous membranes, lie on both sides of the oropharynx (part of the throat near the mouth).
They are filters to protect the body from the invasion of microorganisms and produce lymphocytes, disease-fighting white blood cells.
Three pairs of SALIVARY GLANDS surround and empty into the oral cavity.
These exocrine glands produce SALIVA, which lubricates the mouth.
Saliva contains important digestive ENZYMES as well as healing growth factors such as cytokines.
Saliva is released from a PAROTID GLAND, SUBMANDIBULAR GLAND, and SUBLINGUAL GLAND on both sides of the mouth.
Narrow ducts carry saliva into the oral cavity.
The glands produce about 1.5 liters of saliva daily.

6. Page 140
Teeth
The GUMS are the fleshy tissue surrounding the sockets of the TEETH.
There are 32 permanent teeth in the entire oral cavity.
A tooth consists of a CROWN, which shows above the gum line, and a ROOT, which lies within the bony tooth socket.
The outermost layer of the crown, the ENAMEL, protects the tooth.
It is the hardest tissue in the human body. 
DENTIN, the main substance of the tooth, lies beneath the enamel and extends throughout the crown.
Dentin's color ranges from creamy white to yellow, and it affects the color of teeth because enamel is translucent.
The CEMENTUM covers, protects, and supports the dentin in the root.
A PERIODONTAL MEMBRANE surrounds the cementum and holds the tooth in place in the tooth socket.
The PULP lies underneath the dentin.
This soft and delicate tissue fills the center of the tooth.
Blood vessels, nerve endings, connective tissue, and lymphatic vessels are within the pulp canal (ROOT CANAL).
Root canal therapy often is necessary when disease or abscess (pus collection) occurs in the pulp canal.
A dentist opens the tooth from above and cleans the canal of infected tissue, nerves, and blood vessels.
The canal is then disinfected and filled with material to prevent the entrance of microorganisms that could cause decay.

7. Page 143
Pharynx
The PHARYNX (THROAT) is a muscular tube, about 5 inches long, lined with a mucous membrane.
It serves as a passageway both for air traveling from the nose (nasal cavity) to the windpipe (trachea) and for food traveling from the oral cavity to the ESOPHAGUS. 
When swallowing (deglutition) occurs, a cartilaginous flap of tissue, the epiglottis, covers the trachea so that food cannot enter and become lodged there.

8. Page 144
Esophagus
The ESOPHAGUS is a 9- to 10-inch muscular tube extending from the pharynx to the stomach. 
PERISTALSIS is the involuntary, progressive, rhythmic contraction of muscles in the wall of the esophagus (and other gastrointestinal organs) propelling a BOLUS (mass of food) down toward the stomach.
The process is like squeezing a marble through a rubber tube.

9. Stomach Page 145 Food passes from the esophagus into the STOMACH.
The stomach has three main parts: FUNDUS (upper portion), BODY (middle section), and ANTRUM (lower portion).
Rings of muscle called SPHINCTERS control the openings into and leading out of the stomach.
They prevent food from regurgitating (flowing backward from the normal direction).
The LOWER ESOPHAGEAL SPHICTER (LES) relaxes and contracts to move food from the esophagus into the stomach.
The PYLORIC SPHINCTER allows food to leave the stomach and enter the small intestine when it is ready.
Folds in the mucous membrane (MUCOSA) lining the stomach are called RUGAE.
The rugae increase surface area for digestion and contain glands that produce the enzyme PEPSIN to begin digestion of proteins.
HYDROCHLORIC ACID also is secreted to digest protein and kill any bacteria remaining in food.
The stomach prepares food for the small intestine, where further digestion and absorption into the bloodstream take place.
Food leaves the stomach in 1 to 4 hours or longer, depending on the amount and type of food eaten.

10. Page 145
Small Intestine
The SMALL INTESTINE (SMALL BOWEL) extends for 20 feet from the pyloric sphincter to the first part of the large intestine.
It has three parts.
The first section, the DUODENUM, is only 1 foot long.
It receives food from the stomach as well as BILE from the LIVER and GALLBLADDER and pancreatic juice from the PANCREAS.
Enzymes and bile help digest food before it passes into the second part of the small intestine, the JEJUNUM, about 8 feet long.
The jejunum connects with the third section, the ILEUM, about 11 feet long.
The ileum attaches to the first part of the large intestine.
Millions of tiny, microscopic projections called VILLI line the walls of the small intestine.
The tiny capillaries (microscopic blood vessels) in the villi absorb the digested nutrients into the bloodstream and lymph vessels.

11. Page 146
Large Intestine
The LARGE INTESTINE extends from the end of the ileum to the anus.
It has three main components: the cecum, the colon, and the rectum.
The CECUM is a pouch on the right side that connects to the ileum at the ileocecal valve (sphincter).
The APPENDIX hangs from the cecum.
The appendix has no clear function and can become inflamed and infected when clogged or blocked.
The COLON, about 5 feet long, has four named segments: ascending, descending, transverse, and sigmoid.
The ASCENDING COLON extends from the cecum to the undersurface of the liver, where it turns to the left (hepatic flexure) to become the TRANSVERSE COLON.
The transverse colon passes horizontally to the left toward the spleen and then turns downward (splenic flexure) into the DESCENDING COLON.
The SIGMOID COLON, shaped like an S (sigmoid means resembling the Greek letter sigma, which curves like the letter S), begins at the distal end of the descending colon and leads into the RECTUM.
The rectum terminates in the lower opening of the gastrointestinal tract, the ANUS.
The large intestine receives the fluid waste products of digestion (the material unable to pass into the bloodstream) and stores these wastes until they can be released from the body.
Because the large intestine absorbs most of the water within the waste material, the body can expel solid FECES (stools). 
DEFECATION is the expulsion or passage of feces from the body through the anus.
Diarrhea, or passage of watery stools, results from reduced water absorption into the bloodstream through the walls of the large intestine.

12. Page 158
Mesentery
 Mesentery. The omentum and mesocolon are parts of the mesentery.
The omentum (raised in this figure) actually hangs down like an apron over the intestines.
The mesentery contains blood and lymph vessels.
The lymph nodes in the mesentery are important indicators in the spread of colon cancer (staging of colon cancer).

13. Page 147
Liver
Three important additional organs of the digestive system—the liver, gallbladder, and pancreas—play crucial roles in the proper digestion and absorption of nutrients.
The LIVER, located in the right upper quadrant (RUQ) of the abdomen, manufactures a thick, orange-black, sometimes greenish, fluid called BILE. 
Bile contains cholesterol (a fatty substance), bile acids, and several bile pigments.
One of these pigments, BILIRUBIN, is produced from the breakdown of hemoglobin during normal red blood cell destruction.
Bilirubin travels via the bloodstream to the liver, where it is conjugated or converted into a water-soluble form.
Conjugated bilirubin is then added to bile and enters the intestine (duodenum).
Bacteria in the colon degrade bilirubin into a variety of pigments that give feces a brownish color. Bilirubin and bile leave the body in feces.
If the bile duct is blocked or the liver damaged and unable to excrete bilirubin into bile, the bilirubin remains in the bloodstream, causing JAUNDICE (hyperbilirubinemia)—yellow discoloration of the skin, whites of the eyes, and mucous membranes.
Figure 5-10 reviews the path of bilirubin from red blood cell destruction (hemolysis) to elimination with bile in the feces.
Besides producing bile, the liver has several other vital and important functions:
• Maintaining normal blood GLUCOSE (sugar) levels.
The liver removes excess glucose from the bloodstream and stores it as GLYCOGEN (starch) in liver cells.
When the blood sugar level becomes dangerously low, the liver converts stored glycogen back into glucose via a process called GLYCOGENOLYSIS. 
In addition, when the body needs sugar, the liver can convert proteins and fats into glucose, by a process called GLYCONEOGENESIS.
• Manufacturing blood proteins, particularly those necessary for blood clotting
• Releasing bilirubin, a pigment in bile
• Removing poisons (toxins) from the blood

14. Page 147
Gallbladder
The liver continuously releases bile, which then travels through the HEPATIC DUCT to the CYSTIC DUCT. 
The cystic duct leads to the GALLBLADDER, a pear-shaped sac under the liver, which stores and concentrates the bile for later use.
After meals, in response to the presence of food in the stomach and duodenum, the gallbladder contracts, forcing the bile out the cystic duct into the COMMON BILE DUCT.
Meanwhile, the PANCREAS secretes pancreatic juices (enzymes) that are released into the PANCREATIC DUCT, which joins with the common bile duct just as it enters the DUODENUM.
The duodenum thus receives a mixture of bile and pancreatic juices.
Bile has a detergent-like effect on fats in the duodenum.
In the process of EMULSIFICATION, bile breaks apart large fat globules, creating more surface area so that enzymes from the pancreas can digest the fats.
Without bile, most of the fat taken into the body remains undigested.
The PORTAL VEIN brings blood to the liver from the intestines.
Nutrients from digested foods pass into the portal vein directly after being absorbed into the capillaries of the small intestine, thus giving the liver the first chance to use the nutrients.

15. Pages 147 – 148
Pancreas
The PANCREAS is both an EXOCRINE and an ENDOCRINE organ.
As an exocrine gland, it produces enzymes to digest starch, such as AMYLASE (amyl/o = starch, -ase = enzyme), to digest fat, such as LIPASE (lip/o = fat), and to digest proteins, such as PROTEASE (prote/o = protein).
These pass into the duodenum through the pancreatic duct.
As an endocrine gland (secreting into the bloodstream), the pancreas secretes INSULIN. 
This hormone, needed to help release sugar from the blood, acts as a carrier to bring glucose into cells of the body to be used for energy.

16. Signs and Symptoms Pages 159-161 Anorexia Flatus Ascites Hematochezia
Borborygmi
Jaundice
Constipation
Melena
Diarrhea
Nausea
Dysphagia
Steatorrhea
Eructation
ANOREXIA (ăn-ō-RĔK-sē-ă) Lack of appetite – It is often a sign of malignancy or liver disease. Anorexia nervosa is loss of appetite with emotional problems such as anger, anxiety, & irrational fear of weight gain. It is an eating disorder & is discussed along with a similar eating disorder, bulimia nervosa
ASCITES (ă-SĪ-tēz) Abnormal accumulation of fluid in the abdomen – This condition occurs when fluid passes from the bloodstream & collects in the peritoneal cavity. It can be a sign of neoplasm or inflammatory disorders in the abdomen, venous hypertension (high blood pressure) caused by liver disease (cirrhosis), heart failure. TREATMENT for ascites includes administration of diuretic drugs & paracentesis to remove abdominal fluid. PICTURE – Ascites in a male patient. The photograph was taken after paracentesis (puncture to remove fluid from the abdomen) was performed.
BORBORYGMUS (bŏr-bō-RĬG-mŭs) Rumbling or gurgling noise produced by hyperactive movement of gas, fluid, or both in the gastrointestinal tract – often are present in cases of gastroenteritis & diarrhea
CONSTIPATION (cŏn-stĭ-PĀ-shŭn) Difficulty in passing (eliminating) feces (stool) – Occurs when peristalsis is slow, stools are dry & hard. A diet with plentiful fruits, vegetables, & water is helpful. Laxatives & cathartics are medication to promote movement of stools.
DIARRHEA (dī-ăh-RĒ-ă) Frequent passage of loose, watery stools. Abrupt onset of diarrhea immediately after eating suggests acute infection or toxin in the gastrointestinal tract. Untreated, severe diarrhea may lead to dehydration. Antidiarrheal drugs are helpful.
DYSPHAGIA (dĭs-PHĀ-jē-ă) Difficulty in swallowing – This sensation feels like a "lump in the throat" when a swallowed bolus fails to progress, either because of a physical obstruction (obstructive dysphagia) or because of a motor disorder in which esophageal peristalsis is not coordinated (motor dysphagia)
ERUCTATION (ē-rŭk-TĀ-shŭn) Gas expelled from the stomach through the mouth – also called belching.
FLATUS (FLĀ-tŭs) Gas expelled through the anus. One sign of a bowel obstruction is the inability to pass flatus.
HEMATOCHEZIA (hē-mă-tō-KĒ-zē-ă) Passage of bright red blood from the rectum. The cause of hematochezia is usually hemorrhoids, but can also be colitis, ulcers, polyps, or cancer.
JAUNDICE (JĂWN-dĭs) A symptom of illness marked by yellow-orange discoloration of the skin and whites of the eyes resulting from excess bilirubin in the blood (hyperbilirubinemia). It can occur when: (1) excessive destruction of erythrocytes, as in hemolysis, causes excess bilirubin in the blood; (2) malfunction of liver cells (hepatocytes) due to liver disease prevents the liver from excreting bilirubin with bile; or (3) obstruction of bile flow, such as from choledocholithiasis or tumor, prevents bilirubin in bile from being excreted into the duodenum – PICTURE -  Jaundice due to liver disease.
MELENA (MĔL-ĕ-nă or mĕ-LĒ-nă) Black, tarry stools; feces containing digested blood – results from bleeding in the upper gastrointestinal tract (duodenal ulcer). A positive result on stool guaiac testing indicates blood in the stool.
NAUSEA (NĂW-zē-ă) Unpleasant sensation in the stomach with a tendency to vomit – Common causes are motion sickness, early pregnancy, & viral gastroenteritis. Nausea & vomiting may be symptomatic of a perforation (hole in the wall) of an abdominal organ; obstruction of a bile duct, stomach, or intestine; or exposure to poisons
STEATORRHEA (stē-ă-tō-RĒ-ă) Discharge of fat in the feces due to improper digestion and malabsorption of fat – It is the production of frothy, foul-smelling fecal matter that often floats in the toilet. This may occur with disease of the pancreas (pancreatitis) when pancreatic enzymes are not excreted.

17. Pathology: Oral Cavity and Teeth
Page 161
Pathology: Oral Cavity and Teeth
Aphthous stomatitis
Dental caries
Herpetic stomatitis
Oral leukoplakia
Periodontal disease
APHTHOUS STOMATITIS (ĂF-thŭs stō-mă-TĪ-tĭs) Inflammation of the mouth with small, painful ulcers; canker sores – The ulcers associated with this condition are commonly called canker sores; the cause is unknown. PICTURE B
DENTAL CARIES (DĔN-tăl KĂR-ēz) Tooth decay – Dental plaque results from the accumulation of foods, proteins from saliva, & necrotic debris on the tooth enamel. Bacteria grow in the plaque & cause production of acid that dissolves the tooth enamel, resulting in a cavity (area of decay). If the bacterial infection reaches the pulp of the tooth, root canal therapy may be necessary. PICTURE C
HERPETIC STOMATITIS (hĕr-PĔT-ĭk stō-mă-TĪ-tĭs) Inflammation of the mouth caused by infection with the herpes virus; painful, fluid-filled blisters are produced on the lips, palate, gums, & tongue, commonly called fever blisters or cold sores. It is caused by herpes simplex virus type 1 (HSV1). Herpes genitalis (due to HSV2) involves the reproductive organs. Both conditions are highly contagious. PICTURE D
ORAL LEUKOPLAKIA (ŎR-ăl lū-kō-PLĀ-kē-ă) White plaques or patches on the mucous membranes of the mouth – This precancerous lesion can result from chronic tobacco use (pipe smoking or chewing tobacco). Malignant potential is assessed by microscopic study of biopsied tissue. PICTURE E
PERIODONTAL DISEASE (pĕr-ē-ō-DŎN-tăl dĭ-ZĒZ) Inflammation and degeneration of gums, teeth, and surrounding bone – Gingivitis occurs as a result of accumulation of dental plaque & dental calculus or tartar (a yellow-brown calcified deposit on teeth). In gingivectomy, the periodontist uses a metal instrument to scrape away plaque & tartar from teeth; any pockets of pus (pyorrhea) are then drained & removed to allow new tissue to form. Localized infections are treated with systemic antibiotics

18. Pathology: Upper GI Tract
Pages 162 – 163
Pathology: Upper GI Tract
Achalasia
Esophageal cancer
Esophageal varices
Gastric carcinoma
ACHALASIA (ăk-ăh-LĀ-zē-ă) Failure of the lower esophagus sphincter (LES) to relax; dilation of the esophagus and loss of peristalsis so that food cannot pass easily through the esophagus. Both failure or the LES to relax & the loss of peristalsis cause dilatation (widening) of the esophagus above the constriction. Physicians recommend a bland diet low in bulk & mechanical stretching of the LES to relieve symptoms. PICTURE
ESOPHAGEAL CANCER (ĕ-sŏf-ă-JĒ-ăl KăN-sĕr) Malignant tumor of the esophagus
The most common symptom of esophageal cancer is difficulty swallowing (dysphagia). Smoking & chronic alcohol use are major risk factors. Long-term irritation of the esophagus caused by gastric reflux is a premalignant condition called Barrett esophagus. Surgery, radiation therapy, & chemotherapy are treatment options.
ESOPHAGEAL VARICES (ĕ-sŏf-ă-JĒ-ăl VĂR-ĭ-sēz) Swollen, twisted veins at the lower end of the esophagus. Liver disease (such as cirrhosis & chronic hepatitis) causes increased pressure in veins near & around the liver (portal hypertension). This leads to enlarged, tortuous esophageal veins with danger of hemorrhage (bleeding). Treatment may include banding (tying off the swollen esophageal veins) or sclerotherapy (injecting veins with a solution that closes them). Drug therapy to lower portal hypertension can be used to decrease the risk of variceal bleeding. PICTURE
GASTRIC CANCER (GĂS-trĭk KĂN-sĕr) Malignant tumor of the stomach; stomach cancer – RISK FACTOR: Smoking, alcohol use, & chronic gastritis associated with bacterial infection. TREATMENT: Gastric endoscopy & biopsy diagnose the condition. Cure depends on early detection & surgical removal.

19. Upper GI Tract (Cont’d)
Pages 162 – 163
Upper GI Tract (Cont’d)
Gastroesophageal reflux disease (GERD)
Hernia
Peptic ulcer
GASTROESOPHAGEAL REFLUX DISEASE (găs-trō-ĕ-sŏf-ă-JĒ-ăl RĒ-flŭx dĭ-ZĒZ) Backflow of solids and liquid return to the mouth from the stomach. SYMPTOM: Heartburn [a burning sensation caused by regurgitation of hydrochloric acid from the stomach to the esophagus]. Chronic exposure of esophageal mucosa to gastric acid & pepsin (an enzyme that digests protein) leads to reflux esophagitis. Drug treatment for GERD includes antacid (acid-suppressive) agents & medication to increase the tone of the LES.
HERNIA (HĔR-nē-ă) = Protrusion of an organ or part through the tissues & muscles normally containing it.
HIATAL HERNIA (hī-Ā-tăl HĔR-nē-ă) Protrusion of the upper portion of the stomach upward through the diaphragm. This condition can lead to GERD.
INGUINAL HERNIA (ĬNG-wĭ-năl HĔR-nē-ă) A small loop of the bowel protrudes through a weakened lower abdominal muscle. Surgical repair of inguinal hernias is known as herniorrhaphy
PEPTIC ULCER (PĔP-tĭc ŬL-sĕr) Open sore or lesion of the mucous membrane of the stomach and duodenum. A bacterium, Helicobacter pylori (H. pylori), is responsible for many cases of peptic ulcer disease. The combination of bacteria, hyperacidity, & gastric juice damages epithelial linings. Drug treatment includes antibiotics, antacids, & agents to protect the lining of the stomach & intestine.

20. Pathology: Lower GI Tract
Pages 164 & 166
Pathology: Lower GI Tract
Anal fistula
Colonic polyps
Colorectal Cancer
Crohn disease
Diverticulosis
Dysentery
ANAL FISTULA (Ā-năl FĬS-tū-lă) Abnormal tube-like passageway near the anus. The fistula often results from a break or fissure in the wall of the anus or rectum, or from an abscess (infected area) there. PICTURE – Anal fistula and two types of polyps (for the next term)
COLONIC POLYPS (kō-LŎN-ĭk pŏlĭps) Benign growths protrude from the mucous membrane lining the colon. Pedunculated (attached to the membrane by a stalk) and sessile (sitting directly on the mucous membrane). Many polyps are premalignant (adenomatous polyps); these growths often are removed (polypectomy) as a preventative measure & for further examination (biopsy). PICTURE – Multiple polyps of the colon.
COLORECTAL CANCER (kō-lō-RĔK-tăl KĂN-sĕr) Adenocarcinoma of the colon or the rectum or both.
Colorectal cancer can arise from polyps in the colon or rectal region. Diagnosis is determined by detecting blood in stool & by colonoscopy. Prognosis depends on the stage of the tumor, including size, depth of invasion, & involvement of lymph nodes. Surgical treatment may require excision of a major section of colon with rejoining of the cut ends (anastomosis). Chemotherapy & radiotherapy are administered as needed. PICTURE – Adenocarcinoma of the colon. This tumor has “heaped-up” edges and an ulcerated central portion.
CROHN DISEASE ( krōn dĭ-ZĒZ) Inflammatory bowel disease marked by anorexia, diarrhea, severe abdominal pain, fever, weakness and weight loss. Both Crohn disease & ulcerative colitis are forms of inflammatory bowel disease (IBD). TREATMENT is with drugs that control inflammation & other symptoms or by surgical removal of diseased portions of the intestine, with anastomosis of remaining parts.
DIVERTICULOSIS (dī-vĕr-tĭk-ū-LŌ-sĭs) Abnormal outpouchings [DIVERTICULA (dī-vĕr-TĬK-ū-lă) Small, pouch-like herniations through the muscular wall of a tubular organ such as the colon] in the intestinal wall of the colon without inflammation. DIVERTICULITIS (dī-vĕr-tĭk-ū-LĪ-tĭs) is a complication of diverticulosis. [Inflammation of diverticula because fecal matter has becomes trapped in diverticula; SYMPTOMS: abdominal pain and rectal bleeding] Initial treatment for an attack of diverticulitis includes a liquid diet & oral antibiotics. In severe cases, the patient may need hospitalization, intravenous antibiotics, & surgery to remove the affected area of the colon with anastomosis of the cut ends.
PICTURE – Diverticula (resulting in diverticulosis) form when the mucous membrane lining of the colon bulges through the weakened muscular wall.
DYSENTERY (DĬS-ĕn-tĕr-ē) Painful, inflamed intestines commonly cause by bacterial infection – Often occurring in the colon, dysentery results from ingestion of food or water containing bacteria (salmonellae or shigellae), amebae (one-celled organisms), or viruses. SYMPTOMS: bloody stools, abdominal pain, & sometimes fever.

21. Lower GI Tract (Cont’d)
Pages 164 & 166
Lower GI Tract (Cont’d)
Hemorrhoids
Ileus
Inflammatory bowel disease (IBD)
Intussusception
Irritable Bowel Syndrome (IBS)
Ulcerative colitis
Volvulus
HEMORRHOIDS (HĔM-ō-roydz) Swollen, twisted varicose veins in the rectal region. Varicose vein can be internal (within the rectum) or external (outside the anal sphincter). CAUSES: Pregnancy & chronic constipation, which put pressure on anal veins.
ILEUS (ĬL-ē-ŭs) Failure of peristalsis with obstruction of the intestines – Surgery, trauma, or bacterial injury to the peritoneum can lead to a paralytic ileus (acute, transient loss of peristalsis).
INFLAMMATORY BOWEL DISEASE (ĭn-FLĂ-mă-tō-rē BŎW-ĕl dĭ-ZĒZ) Severe inflammation of the small and large intestine (colon); EXAMPLES: Crohn disease and ulcerative colitis
INTUSSUSCEPTION (ĭn-tŭs-sŭs-SĔP-shŭn) One portion of the intestine slips into an adjoining part; telescoping of the intestines – It often occurs in children & at the ileocecal region. Intestinal obstruction with pain & vomiting can occur. A barium enema can diagnose & may successfully reduce the intussusception. Otherwise, surgery to remove the affected segment of bowel (followed by anastomosis) may be necessary.
IRRITABLE BOWEL SYNDROME (ĬR-ĭ-tă-bl BŎW-ĕl SĬN-drōm) Group of gastrointestinal symptoms (abdominal pain, diarrhea, constipation, and bloating) associated with stress and tension or occur after infection. TREATMENT: includes a diet high in bran & fiber & laxatives plus antidiarrheal to establish regular bowel movements. Also known as irritable colon and spastic colon.
These are disorders of how the gastrointestinal tract functions, but without structural or biochemical abnormalities.
ULCERATIVE COLITIS (ŬL-sĕr-ă-tĭv kō-LĪ-tĭs) Chronic inflammation of the colon and rectum with the presence of ulcers; an inflammatory bowel disease – The idiopathic, chronic, recurrent diarrheal disease (an inflammatory bowel disease) manifests with rectal bleeding & pain. Often beginning in the colon, the inflammation spreads proximally, involving the entire colon. Drug treatment & careful attention to diet are recommended. Resection of diseased bowel with ileostomy may be necessary. In some cases it is cured by total colectomy. Patients with ulcerative colitis are at a higher risk for developing colon cancer.
VOLVULUS (VŌL-vū-lŭs) Twisting of the intestine on itself; this causes intestinal obstruction, Severe pain, nausea & vomiting, & absence of bowel sounds are clinical features. Surgical correction is necessary to prevent necrosis of the affected segment of the bowel.

22. Pathology: Liver, Gallbladder, & Pancreas
Page 167
Pathology: Liver, Gallbladder, & Pancreas
Cholelithiasis
Viral hepatitis
Cirrhosis
Hepatocellular carcinoma (HCC)
Pancreatic cancer
Pancreatitis
CHOLELITHIASIS (kō-lē-lĭ-THĪ-ă-sĭs) Abnormal condition of forming gallstones – Calculi (stones) prevent bile from leaving the gallbladder & bile ducts. Many patients remain asymptomatic & do not require treatment; symptoms related to gallbladder stones are either biliary colic (pain from blocked ducts) or cholecystitis (inflammation & infection of the gallbladder), both of which require treatment.
Currently, laparoscopic or minimally invasive surgery (laparoscopic cholecystectomy) can be performed to remove the gallbladder & stones.
CIRRHOSIS (sĭr-RŌ-sĭs) Chronic, degenerative disease of the liver – commonly the result of chronic alcoholism, viral hepatitis, iron overload, or other causes. Lobes of the liver become scarred with fibrous tissue, hepatic cells degenerate, & the liver is infiltrated with fat. Cirrh/o means yellow-orange, which describes the liver's color caused by fat accumulation.
Hepatocellular Carcinoma (HCC) = Liver cancer
Cancer that starts in the liver is primary liver cancer (as opposed to secondary liver cancer, which starts in another organ & metastasizes to the liver). HCC is commonly associated with hepatitis B & C virus infections & cirrhosis due to chronic alcohol use. Nonalcoholic steatohepatitis (NASH) is fatty infiltration of the liver, which may progress to cirrhosis & HCC. Surgery & chemotherapy are therapeutic options.
Hepatocellular carcinomas produce alpha-fetoprotein (AFP), a tumor marker that is elevated in the blood in patients with this cancer. AFP is used as a screen for HCC in patients with cirrhosis. Liver cancers also can arise from the gallbladder.
PANCREATIC CANCER (păn-krē-Ă-tĭc KĂN-sĕr) Malignant tumor of the pancreas
It often occurs in the head of the pancreas (closer to the duodenum), where it can block ducts.
Although the cause is unknown, pancreatic cancer is more common in smokers & people with diabetes & chronic pancreatitis. SYMPTOMS: abdominal or back pain, fatigue, jaundice, anorexia, diarrhea, & weight loss. TREATMENT: pancreatoduodenectomy (Whipple procedure).
PANCREATITIS (păn-krē-ă-TĪ-tĭs) Inflammation of the pancreas
Digestive enzymes attack pancreatic tissue & damage the gland.
Other etiologic factors include chronic alcoholism, drug toxicity, gallstone obstruction of the common bile duct, & viral infections. TREATMENT: medications to relieve epigastric pain, intravenous fluids, bowel rest, & subtotal pancreatectomy if necessary.
VIRAL HEPATITIS (VĪ-răl hĕp-ă-TĪ-tĭs) Inflammation of the liver caused by a virus
In all types, liver enzyme levels may be elevated, indicating damage to liver cells. SYMPTOMS: malaise, anorexia, hepatomegaly, jaundice, & abdominal pain.
HEPATITIS A: caused by the hepatitis A virus (HAV). Spread by contaminated food or water & characterized by slow onset of symptoms.
HEPATITIS B: caused by the hepatitis B virus (HBV). Spread by sexual contact, blood transfusions, or the use of contaminated needles or may be acquired by maternal to fetal transmission. Severe infection can cause destruction of liver cells, cirrhosis, or death. A vaccine that provides immunity is available & recommended for persons at risk for exposure.
HEPATITIS C: caused by the hepatitis C virus (HCV). Spread by blood transfusions or needle inoculation (such as among intravenous drug users sharing needles). The acute illness may progress to chronic hepatitis & hepatocellular carcinoma. Two new drugs, simeprevir (Olysio) & sofosbuvir (Sovaldi), are effective for treating HCV infection.