Lecture 19 CH23 Gastrointestinal System PDF

The Gastrointestinal Tract Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com. Learning Objectives Identify the major types of cleft lip and cleft palate deformity. 2. Explain the pathogenesis of dental caries and periodontal disease, and describe...

The Gastrointestinal Tract Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com. Learning Objectives Identify the major types of cleft lip and cleft palate deformity. 2. Explain the pathogenesis of dental caries and periodontal disease, and describe prevention and treatment. 3. Name and describe the three most common lesions of the esophagus that lead to esophageal obstruction. 4. Describe the common types of gastritis and their clinical manifestations. 5. Explain the pathogenesis of peptic ulcer. Describe the three major complications of peptic ulcer and their treatment. Name the methods of treatment. 6. Differentiate between appendicitis and Meckel diverticulitis in terms of pathogenesis, clinical manifestations, and treatment. 7. Describe the common types of chronic and acute enteritis and their clinical manifestations. Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com 1. Learning Objectives Describe the pathogenesis of diverticulitis, and explain the role of diet in the development of lesions. 9. Name the causes, clinical manifestations, complications, and treatment of intestinal obstruction, carcinoma of the colon, and diverticulosis of the colon. 10. Understand the major eating disturbances and their effects. Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com 8. Gastrointestinal Tract Functions: ▪ Elimination of wastes Composed of: Oral cavity Esophagus, stomach, small and large intestines, rectum (mouth to anus) https://en.wikipedia.org/wiki/Gastrointestinal_tract Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Digestion and absorption of food, reabsorption of water Diagnosis of Gastrointestinal Diseases Fecal analysis (culture, blood) Radiologic examination (X ray/CT) ▪ Examine areas that cannot be readily visualized ▪ Evaluate motility problems ▪ Visualize contours of gastrointestinal tract mucosa ▪ Identify location and extent of disease with contrast ▪ Upper gastrointestinal tract (UGI) –Barium swallow ▪ Colon: Barium enema (BE) MRI/ultrasound Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Endoscopic procedures ▪ Directly visualize and biopsy abnormal areas, such as esophagus, stomach, intestines Abnormalities of the Oral Cavity: Cleft Lip and Cleft Palate Palate formed by two masses of tissues that grow medially and fuse at midline to separate as nose and mouth Maldevelopment leads to defects ▪ 1 per 1,000 births ▪ Multifactorial inheritance pattern ▪ Upper lip and jaw (cleft lip), Palate (cleft palate) Can lead to liquid aspiration, airway obstruction, feeding difficulties Surgical correction (cheiloplasty) ▪ Cleft lip: Soon after birth ▪ Cleft palate: 1 to 2 years of age with speech therapy to correct nasal speech Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Embryologically, face and palate formed by coalescence of cell masses that merge to form facial structures Abnormalities of Tooth Development Enamel forms on teeth at specific times during embryologic period. ▪ Tetracycline (antibiotic): Administered during enamel formation causes permanent yellow-gray to brown discoloration of the crown of teeth Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Teeth: Specialized structures that develop in tissues of the jaws – dentin (solid structure) covered by enamel (protection) surrounds pulp, embedded in jaws ▪ Two sets ▪ Temporary or deciduous teeth (20 teeth) formed before birth and emerge in childhood ▪ Permanent teeth (32 teeth) develop in childhood and push on roots to replace temporary set ▪ Missing teeth or extra teeth: Common abnormality – failure of tooth buds (familial trait) Dental Caries and Periodontal Disease ▪ Plaque combined with action of bacteria results in tooth decay (caries) ▪ Dental cavity: Loss of tooth structure (decay) from bacterial action (acidic erosion of enamel and decay of dentin (decreased density, softening and discoloration of teeth) ▪ Continuation to destruction of pulp leads to inflammation (pulpitis), throbbing pain (tooth ache) and eventual abscess development in the jaw. ▪ Saliva has protective role – dry mouth (xerostoma) have increased risk of cavity development ▪ Gingivitis: Inflammation of the gums due to masses of bacteria and debris accumulating around base of teeth – can lead to periodontal disease ▪ Inflammation extends to tissues that support teeth; forms small pockets of infection between teeth and gums causing teeth to loosen and fall out Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Oral cavity: Diverse collection of aerobic and anaerobic bacteria that mix with saliva, forming sticky biofilm on teeth (dental plaque) Inflammation of the Oral Cavity: Stomatitis: Inflammation of the oral cavity Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Causes: ▪ Irritants: Alcohol, tobacco, hot or spicy foods ▪ Infectious agents: Herpesvirus(HSV), HPV, Candida albicans (fungus), bacteria that cause trench mouth – advanced form of gum disease (bleeding, swelling, pain, ulcers) ▪ Canker sores: small painful superficial ulcer of oral mucosa with inflammatory border (red) painful – not contagious Carcinoma of the Oral Cavity Erythroplakia –depressed red lesions frequently associated with dysplasia and carcinoma Arises from squamous epithelium of the: Lips, Cheek, Tongue, Palate, Back of throat, nasal cavity Can also have cancer develop in salivary glands Oral cancers readily metastasize – many nearby LN in head and neck Oral cancers – strong association with smoking and alcohol use HPV (serotype 16) – responsible for 75% of head/neck cancers (slow progression – decades) Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Leukoplakia – white lesions - rarely indicate possible dysplasia (20%) Esophagus Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Muscular tube that extends from pharynx to stomach with sphincters at upper and lower ends ▪ Upper sphincter relaxes to allow passage of swallowed food ▪ Food progresses through smooth muscle contraction (peristaltic contractions) ▪ Lower (gastroesophageal or cardiac) sphincter relaxes to allow passage of food to the stomach Esophageal sphincter dysfunction Diseases ▪ Failure of cardiac (gastroesophageal) sphincter to function properly ▪ Tears in lining of esophagus from retching and vomiting from repetitive, intermittent, vigorous contractions that increase intra-abdominal pressure ▪ Esophageal obstruction from carcinoma, food impaction, or stricture (esophageal webs, rings) Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Symptoms ▪ Difficulty swallowing (dysphagia) ▪ Substernal discomfort or pain (heartburn-GERD) ▪ Inability to swallow (aphagia - complete obstruction) ▪ Regurgitation of food or fluids into trachea causing aspiration, choking and coughing Esophagus – cardiac LES dysfunction Complications of incompetent cardiac sphincter ▪ Reflux esophagitis: irritation, Inflammation – Asthma risk ▪ Ulceration and scarring of squamous mucosal lining ▪ Barrett esophagus: Glandular metaplasia; change from squamous to columnar epithelium increases risk for cancer Treatment: Lifestyle modification, diet (alcohol), antacids Drugs – reduce acid production in stomach (proton pump inhibitors -PPI) Surgery – if hiatal hernia/esophageal rings Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Two major types of disturbances of cardiac sphincter (lower esophageal sphincter-LES) 1. Achalasia: Sphincter fails to open properly due to malfunction of nerve plexus; esophagus becomes dilated proximal to constricted sphincter from food retention ▪ Inability to swallow fluids and food (dysphagia) ▪ Treatments: drugs (relax sphincter) – injection of botulinum toxin (block nerve signals), Periodic stretching of sphincter, surgery 2. Incompetent cardiac sphincter: Sphincter remains open; gastric juices leak back into esophagus (GERD) Esophageal obstruction http://www.oeso.org/OESO/books/Vol_5_Eso_Junction/Articles/art416.html Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Causes of esophageal obstruction ▪ Carcinoma: Can arise anywhere in esophagus Tumor narrows lumen of esophagus, infiltrates surrounding tissue, can invade trachea (tracheoesophageal fistula) Barretts esophagus: adenocarcinoma squamous cell carcinoma : HPV, alcohol/ toxic chemicals ▪ Food impaction: improperly chewed food – poor dentition and eating habits ▪ Stricture: From scar tissue due to necrosis and inflammation from corrosive chemicals, such as lye ▪ Hiatal hernia, esophageal rings Gastric Mucosal Tears Linear tears in the mucosa or lining of esophagus caused by vigorous abdominal contractions (blood loss) Leads to bloody vomit (hematemesis) Most heal on own, or use minor surgical (cautery/ injections) repair in severe cases Boerhaave syndrome: rupture of esophagus / full thickness perforation – high mortality with treatment (30%) always fatal without surgery and antibiotic Tx Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Mallory Weiss syndrome: Caused by retching and vomiting – often related to excess alcohol intake or repeated forced vomiting (Bulimia) Diseases of the Stomach: Acute Gastritis May be associated with mucosal ulceration or bleeding Most commonly from nonsteroidal anti-inflammatory drugs (NSAIDs) that inhibit cyclooxygenase (COX) enzyme: Aspirin, ibuprofen, naproxen ▪ COX-1: Promotes synthesis of prostaglandin that protects gastric mucosa ▪ COX-2: Promotes synthesis of prostaglandin that mediates inflammation Alcohol: Gastric irritant; stimulates gastric acid secretion Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Inflammation of the gastric lining, self-limited inflammation of short duration Helicobacter pylori Gastritis Small, gram-negative organisms that colonize the surface of gastric mucosa ▪ Produce urease that decomposes urea, a product of protein metabolism, into ammonia ▪ Ammonia neutralizes gastric acid, allowing organisms to flourish; organisms also produce enzymes that break down mucus layer ▪ Common infection that increases with age (50% by age 50) – not all are symptomatic ▪ Spreads from person-to-person through close contact and fecal–oral route ▪ Chronic gastritis leads to increased risk of gastric carcinoma: Intestinal metaplasia and Increased risk of malignant lymphoma (mucosa-associated lymphoid tissue [MALT]) ▪ Can also lead to formation of peptic ulcers (75% of patients with gastric ulcers have H. Pylori infection) Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Grow within layer of mucus covering epithelial cells lining the stomach Peptic Ulcer Complications: ▪ Chronic hemorrhage (ulceration erodes into blood vessel), ▪ perforation (erosion through wall – exit of gastric contents into peritoneal cavity – peritonitis) ▪ obstruction from scarring Treatment • Antacids, PPI • Antibiotic therapy: Against H. pylori (90% effective) • Surgery if medical therapy fails or to correct perforations Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Pathogenesis ▪ Digestion of mucosa due to increased acid secretions and digestive enzymes (gastric acid and pepsin) ▪ H. pylori injures mucosa directly and through stimulation of increased acid secretion by gastric mucosa ▪ Common sites: Distal stomach or proximal duodenum Carcinoma of the Stomach Diagnosis: Biopsy by means of gastroscopy Treatment: ▪ Surgical resection of affected part, surrounding tissue, and lymph nodes ▪ Can be combined with radiation and chemotherapy Long-term survival: Relatively poor; often far advanced at time of diagnosis Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Manifestations ▪ Vague upper abdominal discomfort ▪ Iron-deficiency anemia (chronic blood loss from ulcerated surface of tumor) Inflammatory Diseases of the Intestines: Enteritis Bacterial enteritis –similar to viral infection in mild cases, but depending on strain and infection can be more severe (toxin production): ▪ Common agents: Vibrio chloerae, E. Coli– severe cases can lead to prolonged disease and ulceration in severe infection and may produce bloody diarrhea ▪ major cause of death in developing world (dehydration/ malnutrition/electrolyte imbalance. Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Acute enteritis ▪ Intestinal infections; common; of short duration ▪ Commonly rotavirus (infants, children – oral/fecal) or norovirus (adults – highly contagious ) ▪ Abrupt onset : nausea, vomiting, abdominal discomfort, diarrhea ▪ Self limiting disease that resolves in a few days Disturbances in Bowel Function :food intolerance Food intolerance: Crampy abdominal pain, distention, flatulence, loose stools Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Lactose intolerance ▪ Unable to digest lactose into glucose and galactose for absorption due to lactase deficiency ▪ Enzyme abundant in infants and young children – reduction with aging ▪ Unabsorbed lactose remains in intestinal lumen and raises osmotic pressure of bowel contents ▪ Fermented by bacteria in colon, yielding lactic acid that further increases intraluminal pressure ▪ Genetic component: common in almost all adults of Asian decent; 90% of Native Americans; 70% of African decent , 20% Caucasian decent Disturbances Bowel Function: Celiac Disease Diagnosis: Clinical features (steatorrhea), CT scan (inflammation, wall thickening) endoscopy and biopsy of intestinal mucosa, presence of anti transglutaminase antibodies Treatment: • Gluten-free diet • Drugs used in refractory disease (Steroids, immune suppressants) Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Celiac disease – gluten intolerance ▪ Gluten – specifically gliadin protein in wheat, rye, barley ▪ immune related disorder T cell mediated – primarily in small intestine ▪ Inflammation– increased cancer risk ▪ Leads to atrophy of intestinal villi malabsorption ▪ Chronic diarrhea impairs absorption of fats and nutrients; weight loss – poor growth, vitamin deficiencies that can lead to anemia Irritable Bowel Syndrome Also known as spastic colitis or mucous colitis ▪ diarrhea, constipation or alternating bouts of diarrhea and constipation ▪ excessive mucus secreted by colonic mucosal glands Diagnosis made by exclusion – no structural or biochemical anomalies ▪ Rule out pathogenic infections, food intolerance, and inflammatory conditions (Chron’s, Ulcerative colitis etc.) Treatment ▪ identify foods/conditions that may precipitate episodes (stress/anxiety) ▪ Improve intestinal motility (high fibre, low sugar diet) ▪ Reduce emotional tension – counselling/antidepressants Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Episodes of crampy abdominal discomfort, loud gurgling bowel sounds, and disturbed bowel function without structural or biochemical abnormalities Appendix – Vestigial organ? Appendix projects from proximal colon (fingerlike) ▪ Gut flora reservoir? Increased C. Diff when removed ▪ Evidence of importance in immune function – removal associates with increased GI infections https://www.niddk.nih.gov/health-information/digestive-diseases/appendicitis/definition-facts Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Evidence of past importance in predominant vegetable diet (Enlarged in some herbivores rabbit, horse) Inflammatory Diseases of the Bowel: Appendicitis Manifestations/Diagnosis ▪ Generalized abdominal pain localizing in right lower quadrant; rebound tenderness; rigidity ▪ CT and Ultrasound along with blood tests (elevated WBC) Treatment: Antibiotics, Surgery – removal to avoid rupture Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Appendicitis: Most common inflammatory lesion of the bowel ▪ Narrow caliber of appendix may be plugged with fecal material ▪ Secretions of appendix drain poorly, create pressure in appendiceal lumen, compressing blood supply ▪ Bacteria (normally present) invade appendiceal wall, causing inflammation Chronic Enteritis Chronic enteritis: Less common, more difficult to treat than acute enteritis Characterized with periodic flare ups/remissions, systemic manifestations (joint inflammation) with genetic and environmental components (immune related, not autoimmune) Crohn’s disease • Chronic inflammation and ulceration of mucosa with thickening and scarring of entire bowel wall (full thickness) • Causes cramping, diarrhea (bloody/mucous), fatty (steatorrhea) • Inflammation may be scattered with normal intervening areas, or skip areas • Increased risk of cancer • Mouth to anus (most commonly terminal ileum) Treatment: Drugs (corticosteroids) and possible surgical resection of affected part of bowel Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com 2 important types of IBD: Chron’s disease and Chronic ulcerative Colitis Ulcerative Colitis Complications ▪ Bleeding; bloody diarrhea ▪ Perforation: From extensive inflammation with leakage of intestinal contents into peritoneal cavity – life threatening emergency (20% mortality) (toxic megacolon) ▪ Long-standing disease may develop cancer of colon and/or rectum Treatment ▪ Symptomatic and supportive measures (antibiotics, fluids) ▪ Antibiotics, corticosteroids to control flare-ups, Immunosuppressive drugs ▪ Surgical resection Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Ulcerative colitis: Large intestines and rectum ▪ Inflammation is limited to mucosa, bowel not thickened, (unlike in Crohn disease) ▪ Frequently begins in rectal mucosa and spreads until entire colon is involved (continuous segment) Inflammatory Diseases of the Intestines: Colitis Diagnosis: Stool culture: detection of bacterial toxin in stool Treatment: Stop antibiotic treatment; give vancomycin or metronidazole – pulse therapy ▪ Drugs that decrease intestinal motility will prolong illness ▪ PPI use predisposes to C. diff (65% increased risk) ▪ Can result in prolonged illness – months ▪ Fecal transplant Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Antibiotic-associated colitis: Broad-spectrum antibiotics destroy normal intestinal flora ▪ Allows growth of anaerobic spore-forming bacteria, Clostridium difficile, not inhibited by antibiotic taken (spore forming) ▪ Organisms produce toxins, causing inflammation and necrosis of colonic mucosa ▪ Diarrhea, abdominal pain, fever Intestinal Obstructions Conditions that block normal passage of intestinal contents, always considered a serious condition High (or upper) intestinal obstruction (small intestine) ▪ Severe, crampy abdominal pain from vigorous peristalsis ▪ Vomiting (often bilious) with loss of H2O and electrolytes, may result in dehydration Low intestinal obstruction (large intestine ▪ Symptoms less acute and less severe (larger space, harder to obstruct) ▪ Mild, crampy abdominal pain ▪ Moderate distention of abdomen Common causes of intestinal obstruction are adhesions, hernia, tumors, volvulus, intussusception or cancer Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Degree of severity depends on location of obstruction, completeness, interference with blood supply Intestinal Obstructions Hernia ▪ Protrusion of loop of bowel through a small opening, usually in abdominal wall ▪ Herniated loop pushes through peritoneum to form hernial sac ▪ Inguinal, umbilical, femoral Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Adhesions ▪ Adhesive bands of connective tissue that form within the abdominal cavity (often after surgery) ▪ May cause loop of bowel to become kinked, compressed, twisted ▪ Causes obstruction proximal to site of adhesion Intestinal Obstructions: Hernia Umbilical and femoral hernia: Common in both sexes ▪ Umbilical hernia: Loop of bowel protrudes into umbilicus through defect in the abdominal wall ▪ Femoral hernia: Loop of intestine extends under inguinal ligament along course of femoral vessels into the groin Reducible hernia: Herniated loop of bowel can be pushed back into abdominal cavity Incarcerated hernia: Cannot be pushed back Strangulated hernia: Loop of bowel is tightly constricted, obstructing the blood supply to the herniated bowel; requires prompt surgical intervention to prevent infarction Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Inguinal hernia: Common in men; loop of small bowel protrudes through a weak area in inguinal ring and descends downward into scrotum Intestinal Obstructions Volvulus: ▪ impairing blood supply (twisting of mesentery, which carries blood supply) – ischemic bowel/infarct ▪ common site is sigmoid colon ▪ Occurs in infants with congenital intestinal malformation ▪ Can also occur in patients with adhesions Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Rotary twisting of bowel and mesenteryleading to bowel obstruction Intestinal Obstructions Intussusception: ▪ Cause: generally unknown congenital condition, or intestinal infection (children) or tumor (adults) ▪ common site is terminal ileum or tumor site Can lead to bowel infarction from compromised blood supply and result in necrosis Corrected surgically Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Telescoping of a segment of bowel into adjacent segment Mesenteric Thrombosis ▪ Artery supplies blood to small bowel and proximal half of colon ▪ May develop arteriosclerosis ▪ Become occluded by thrombus, embolus, or atheroma ▪ Obstruction causes extensive bowel infarction – medical emergency with poor prognosis Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Thrombosis of superior mesenteric artery Diseases of the Colon and Anus: Diverticulosis and Diverticulitis Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Diverticulosis: Outpouchings or diverticula of colonic mucosa through weak areas in the muscular wall of large intestine (diverticula) ▪ Low-residue (low fiber) diet predisposes to condition as increased intraluminal pressure must be generated to propel smaller stools through colon ▪ Forces weak areas through the muscular walls of the colon ▪ usually asymptomatic, seen in older people ▪ Fecal matter can be trapped causing inflammation (diverticulitis) ▪ Complications: Inflammation, perforation, bleeding, scarring, abscess ▪ Common site: Sigmoid colon (distal section proximal to anus) Diseases of the Colon: Tumors Tumors in small intestine are uncommon – more frequent in the large intestine (Colon) Colonoscopy – used for screening and treatment (cauterization/excision) of precancerous lesions (early detection) Development of colorectal cancers are commonly associated with mutations (inherited or sporadic) in APC (Adenomatous polyposis coli) gene (tumor suppressor gene) – resulting in uninhibited rapid cellular growth resulting in: Benign pedunculated polyps ▪ Frequent ▪ Tips of polyps may erode, causing bleeding ▪ Can be detected and removed by colonoscopy Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Good prognosis when confined to colon (90% 5y sr.) declines rapidly if it has metastasized (14% 5 y sr.) Progression of Colon Cancer Loss of DNA integrity further risks mutations (Ras, p53) that transforms benign adenoma into malignant Carcinoma and spread through metastasis FIGURE 23-23 Stages in the progression of invasive colon cancer. Malignant colon cancer is defined by its ability to invade distant anatomic sites. Photographs courtesy of Kathleen R. Cho, University of Michigan Medical School. Used with permission. Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Rapid growth sets the stage for additional mutations and further growth dysregulation with mutations in Tp53 gene (maintains DNA integrity) Cancer in more distal parts of colon Causes obstruction and symptoms of lower intestinal obstruction (smaller diameter) FIGURE 23-25 Colon carcinoma demonstrated by barium enema. The tumor narrows the lumen of the colon, which appears as a filling defect in the column of barium (arrows). Courtesy of Leonard V. Crowley, MD, Century College. Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Cancer in the Cecum and proximal colon does not cause obstruction because caliber is large and bowel contents are relatively soft • Tumor can ulcerate, bleed; leads to chronic iron-deficiency anemia causing weakness and fatigue Imperforate Anus Two types: 1.Rectum and anus normally formed and extends to level of skin but no anal orifice ▪ Easily treated by incising tissue covering anal opening 2. Entire distal rectum fails to develop, with associated abnormalities of urogenital and skeletal system ▪ Corrected surgically but technically more difficult ▪ Less satisfactory results Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Rare congenital anomaly (1:5000 births), colon fails to acquire a normal anal opening Hemorrhoids Varicose veins (weakened areas) of hemorrhoidal venous plexus that drains rectum and anus Relieved by high-fiber diet rich in fruits and vegetables (large bulky stools), stool softeners (temporary relief), rectal ointment, or surgery (for removal) ▪ Internal hemorrhoids ▪ Involve veins of the lower rectum ▪ May erode and bleed, become thrombosed, or prolapse though anus ▪ External hemorrhoids ▪ Veins of anal canal and perianal skin ▪ May become thrombosed, causing discomfort Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Pregnancy, constipation and straining predispose to development Eating disorders : Obesity About 27% of Canadians are Obese (BMI over 30), another 36% deemed overweight (BMI over 25) – all at increased health risks. Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Any caloric intake that exceeds requirements is stored as adipose tissue and weight is gained ▪ Each pound is storage of approximately 3500 calories ▪ Weight is lost if caloric intake is reduced below the amount required for normal metabolic processes ▪ Not simply a disease of calories consumed: calories used ▪ Chronic and progressive disease, influenced by a variety of genetic, environmental, emotional/mental health factors ▪ Weight control – needs to address these causes to be sustainable and effective ▪ Sometimes caused by endocrine or metabolic disturbances (hypothyroidism, adrenal dysfunction) Obesity : risks ▪ Higher incidence of diabetes, hypertension, cardiovascular disease, and many other diseases ▪ Impaired pulmonary ventilation (weight on chest) ▪ Impaired ability to utilize insulin (develop insulin resistance) ▪ Increased mortality from many if not all diseases including cancer outcomes ▪ Increased stress on bones/joints/ligaments ▪ Treatments/ operation are more complicated and have lower success rates (adipose tissue has poor blood supply, heals slowly and is at risk for infection when compromised ▪ Mental health/depression/poor body image Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Excess fat is harmful to the cardiovascular system (High BP, Atherosclerosis) Obesity: Treatment Treatment Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Reduction of food intake and increase in activity ▪ Dieting can include its own health risks (Atkins/keto) ▪ Small weight losses can have significant health benefits ▪ Underlying causes/variable need to be addressed – complex, lifelong issue (psychological, social, physical, financial) ▪ Many individuals are unable or unwilling to reduce their caloric intake, so other treatments have been proposed and used (diet suppressing drugs) ▪ Ileal bypass ▪ Gastric bypass ▪ Adjustable gastric banding Gastric bypass Bariatric surgery: Can lead to complications from poor absorption like anemia (from B12 and iron deficiency) and osteoporosis (inadequate calcium absorption) If not done in conjunction with causes of obesity, can fail to control weight Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Goal is to restrict the capacity of the stomach without compromising nutrient adsorption Gastric Banding Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Anorexia Nervosa False perception of weight excess – actually too thin Can have a variety of negative impacts on health: malnutrition (anemia, osteoporosis), loss of menstrual function, thyroid decline, fluid and electrolyte imbalance –can lead to death Difficult to treat: complex multi system physiological problems associated with chronic starvation along with phycological treatment and support. Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Continual weight reduction by food restriction and excessive exercise Bulimia Nervosa Repeated episodes of binge eating followed by purging Leads to dental problems (erosion from gastric acids), metabolic alkalosis (from loss of gastric acid), and electrolyte disturbances Mucosa tears are possible (Mallory-Weiss), which may be fatal Similar to Anorexia – treatment is complex combination of treating physical (temporary) and phycological (curative) Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Often remains hidden as patients hide purging behaviors and do not exhibit body wasting that can be easily seen Chronic Malnutrition: starvation Caused by insufficient intake of nutrients; cannot supply the body’s needs ▪ Insufficient food caused by inadequate food supply, poor distribution, or natural disaster ▪ Inability to use food efficiently due to diseases that impair food intake, digestion, or absorption Alcoholism: Its role in malnutrition ▪ High-calorie non-nutrient, 7calories per gram ▪ Inadequate diet because of high caloric intake from alcohol can lead to deficiencies Evaluation and treatment: ▪ Loss of 5% to 10% of normal body weight can be tolerated, 30% can be fatal ▪ Laboratory tests are necessary to determine organ and tissue damage ▪ Slow increase of caloric and protein intake with vitamin and mineral supplements, correction of disturbances caused by deficiency, and correction of fluid and electrolyte balance ▪ Kwashikor (famine) - diets sufficient in calories, but lacks protein (severe edema and skin abnormalities), hair takes on red color. Intestinal changes are hard to reverse, even with proper diet – diarrhea likely Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Identifying persons at risk –children/elderly, poverty, cancer, eating disorders, drug/alcohol abuse ▪ Prevention and early detection is important for early treatment Microbiome ▪ Colonization begins at birth (fetal-sterile) from vaginal canal – c-section? ▪ Maternal seeding is modified by diet/digestion, drug therapy, environment, stress, mental health (Gut/Brain Axis) ▪ Roles in metabolism, nutrition, digestion, brain function, cancer and immune function (competition, antimicrobial compounds) ▪ Lack of Bacterial diversity and/or imbalance implicated in IBD (Chron’s /UC), obesity, type 2 diabetes and atopy (Hygiene hypothesis) – increased in C-section. Fecal Transplant – tx c.Diff with ongoing research for Obesity, IBD, Allergy. Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ 10 times more bacterial cells than cells in our body, over 1000 species of bacteria found in gut of humans, typically 100-200 species per person– increased conc from duodenum to colon The Gastrointestinal Tract Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com.