Abnormalities of Tooth DevelopmentTeeth: specialized structures that develop in tissues of the jawsTwo sets Temporary or deciduous teeth (20 teeth)Permanent teeth (32 teeth)Missing teeth or extra teeth: common abnormalityTetracycline-caused problems:If administered to pregnant women during enamel formation of fetus will cause permanent yellow-gray to brown discoloration of the crown of deciduous teethIf administered to infant or child, will cause permanent staining of crown of permanent teethDental Caries and Periodontal DiseaseCaries = “tooth decay” (latin word for “dry rot”)Within the oral cavity: diverse collection of aerobic and anaerobic bacteria mix with saliva, forming sticky film on teeth (dental plaque)Plaque + action of bacteria result in tooth decay (caries)Dental cavity: loss of tooth structure from bacterial actionGingivitis: inflammation of the gum area near tooth due to masses of bacteria and debris accumulating around base of teethPeriodontal disease: inflammation extends to tissues that support teeth; forms small pockets of infection between teeth and gumsPrevention: proper mouth hygiene (brushing, flossing, fluoride)Carcinoma of the Oral CavityArises from squamous epithelium – Lips, cheek, tongue, palate, back of throatRelatively common (22,000 new cases per year; 6-7000 deaths per year)Cancers of head and neck region account for 5% of all cancers reported; 30% of those occur in the oral cavityTreated by surgical resection and/or radiation therapyRisk Factors: Tobacco/alcohol use, varies by world region (e.g., Betel nut {commonly chewed nut} in part India/Asia)Diseases of the EsophagusThe function of the esophagus is the controlled passage of food to the stomach.Esophageal disease manifests itself as dysphagia, or difficult or painful swallowing.Cancer of the esophagusnarrows the lumen, causing dysphagiamay cause vomiting, bad taste in mouth, bad breath, weight loss because of the inability to eat.spreads into adjacent organs and to remote sites through the lymph vessels, frequently metastasizes before it is detected.Prognosis: PoorEsophagitisEsophagitis, inflammation of the esophagus, causes burning chest pains, known as “heartburn,” which can resemble the pain of heart disease.The pain may follow eating or drinking, and some vomiting of blood may occur.Most common cause is reflux a backflow of the acid contents of the stomach.caused by an incompetent cardiac sphincter, which normally prevents stomach contents from ascending the esophagus.Treatment includes a nonirritating diet, antacids, and acid reducing medications.Frequent small meals are recommended; alcohol should be avoided.Tisone story:Left a bottle of pine sol on the table (thought it was 7Up)Youngest son drank itMost important thing is to NOT throw up so it doesn’t burn the esophagus twiceCarcinoma of the StomachManifestationsVague upper abdominal discomfortIron-deficiency anemia (chronic blood loss from ulcerated surface of tumor)Diagnosis: biopsy by means of gastroscopyTreatment: surgical resection of affected part, surrounding tissue and lymph nodesLong-term survival: relatively poor; often far-advanced at time of diagnosisInflammatory Diseases of the IntestinesAcute enteritis Intestinal infections; common; of short duration Nausea, vomiting, abdominal discomfort, loose stoolsChronic enteritis: less common, more difficult to treatRegional enteritis or Crohn’s disease:Affects the distal ileum (*NOT the whole GI tract)Chronic inflammation and ulceration of mucosa with thickening and scarring of bowel wallInflammation may be scattered with normal intervening areas or “skip areas”Treatment: drugs and possible surgical resection of affected part of bowelColon Diverticulosis & DiverticulitisDiverticulosis precedes DiverticulitisDiverticulosis: outpouchings or diverticula of colonic mucosa through weak areas in the muscular wall of large intestineLow-residue diet predisposes to condition as increased intraluminal pressure must be generated to propel stools through colon (*High fiber diet helps prevent this)Acquired, u sually asymptomatic, seen in older peopleCommon site: sigmoid colon Diverticulitis: inflammation incited by bits of fecal material trapped within outpouchings Complications: inflammation, perforation, bleeding, scarring, abscess Treatment: high fiber diet; antibiotic for infectionCarcinoma of the Colon and RectumLeading cause of death from cancer in the United StatesSymptoms vary according to the site of the malignancy.Change in bowel habits, such as diarrhea or constipationAs tumor grows, there may be abdominal discomfort and pressure.Blood often appears in stoolsContinuous bloodloss from the malignant tumor causes anemia.As the tumor invades underlying tissue, the cancer cells spread through the lymph vessels and veins.Early detection extremely importantPrognosis is poor when not detected earlyDysenteryDysentery is an acute inflammation of the colon, a colitis.The major symptom is diarrheastools contain pus, blood, and mucus.Severe abdominal pain accompanies the diarrhea.Bacteria, parasitic worms, and other microorganisms can cause dysentery.The protozoan Entamoeba histolytica, which is transmitted in feces-contaminated food and water, causes amoebic dysenteryThe LiverLargest organ in body, right upper abdominal area, beneath the diaphragm4 Main functions: 1. Metabolism carbohydrates, protein, and fat delivered through the portal circulation2. Synthesis of plasma proteins, clotting factors3. Storage vitamin B12 and other materials4. Detoxification and excretion: various substancesHas a double blood supplyPortal vein: carries 75% of blood, drains from spleen and GI tract; this blood is rich in nutrients absorbed from intestines, low in oxygenHepatic artery: remaining 25% of blood, high in oxygen, low in nutrientsBoth blood supplies mix in the liver, eventually collecting into right and left hepatic veins that drain into inferior vena cavaBile Formation and ExcretionBile: an aqueous secretion of the liver containing bile salts, cholesterol, and other substancesFormed by the breakdown of red blood cellsWhen red blood cells break down, iron is reused and bilirubin, an iron-free heme pigment, is excreted in the bileSmall quantities of bile are continually present in bloodWhen blood passes through liver, bilirubin is removed by conjugation or by combining bilirubin with glucuronic acidBile is secreted continuallyConcentrated and stored in