lecture one.pptx
- 1. Acute & Chronic inflammation
- 2. Acute inflammation is an immediate response to injury or infection that can cause redness, heat, swelling, pain, and loss of function. •• Hemodynamic changes in acute inflammation are mediated by vasoactive chemicals and, after a transient initial vasoconstriction, produce massive dilation with increased vascular permeability. •• Neutrophils are important WBCs in acute inflammation; they contain granules with many degradative enzymes.
- 3. •• Acute inflammation may result in tissue regeneration, scarring, abscess formation,or Chronic inflammation. •• Cells important in chronic inflammation include macrophages, lymphocytes, eosinophils, and basophils. •• Chronic granulomatous inflammation is a specialized form of chronic inflammation with modified macrophages (epithelioid cells and multinucleated giant cells) usually surrounded by a rim of lymphocytes. A wide variety of diseases can cause chronic granulomatous inflammation, most notably TB, syphilis, leprosy, and fungal infections.
- 5. ESOPHAGUS • Histology • The wall of the esophagus consists of four layers: mucosa, submucosa, muscularis propria, and adventitia. Unlike other areas of the GI tract, the esophagus does not have a distinct serosal covering. • Mucosa: epithelium, lamina propria and muscularis mucosaeEpithelium: nonkeratinized stratified squamous epithelium
- 8. Congenital and Mechanical Disorders 1-Tracheoesophageal fistula may arise as a congenital connection between the esophagus and trachea that is often associated with esophageal atresia. It is often discovered soon after birth because of aspiration. In adults the condition can occur secondary to malignancy, trauma, or iatrogenic causes. 2-Esophageal webs are web-like protrusions of the esophageal mucosa into the lumen which typically present with dysphagia. 3-Achalasia is a failure of the lower esophageal sphincter (LES) to relax with swallowing.The etiology is unknown in most cases; in South America, achalasia may be caused by Chagas disease. Presentation is with progressive dysphagia. The esophagusis characteristically dilated proximal to the lower esophageal sphincter. Microscopically, there is a loss of ganglion cellsin the myenteric plexus.
- 10. Hematemesis and Esophageal Bleeding 1-Mallory-Weiss syndrome is esophageal bleeding due to linear lacerations at the gastroesophageal junction from severe prolonged vomiting; the most common cause is acute alcohol ingestion and/or chronic alcoholism. 2-Esophageal varices are dilated submucosal veins in the lower third of the esophagus, usually secondary to portal hypertension. The most common cause is cirrhosis. Both Mallory-Weiss tears and esophageal varices are associated with alcohol abuse and can present with hematemesis.
- 11. Esophagitis 1-Gastroesophageal reflux disease (reflux esophagitis) is esophageal irritation and inflammation due to reflux of gastric secretions into the esophagus 2-Barrett esophagus is a metaplasia of the squamous esophageal mucosa to a more protective columnar type (intestinal metaplasia). It occurs because of chronic exposure to gastric secretions. Barrett has an increased risk for dysplasia and esophageal adenocarcinoma.
- 13. Cancer definition In biology, cancer is defined as the malignant growth due to uncontrolled cell division. It is now used as a general term for over a hundred diseases characterized by the uncontrolled, abnormal growth of cells. At advanced stages, the cells spread (metastasis) locally or through the blood or lymphatics.
- 14. What are Carcinoma Carcinomas are cancers or malignancies that begin in the epithelial cells
- 15. Carcinoma in situ The neoplastic cells does not penetrate the Basement membrane.
- 16. Esophageal Carcinoma • Squamous cell carcinoma (SCC) of the esophagus is the most common type of esophageal cancer in the world. It affects males more than females; typical age is usually age >50. Risk factors include: • Heavy smoking and alcohol use • Achalasia • Diagnosis is by endoscopy with biopsy.
- 19. SCC OF ESOPHAGUS The normal squamous epithelium at the left merges into the squamous cell carcinoma at the right, which is infiltrating downward. The neoplastic squamous cells are still similar to the normal squamous cells, but are less orderly. This is a well- differentiated squamous cell carcinoma, because the neoplastic cells still have many features of the squamous cell of origin
- 20. a malignant tumour formed from glandular structures in epithelial tissue.. Adenocarcinoma
- 21. Adenocarcinoma of the esophagus -It arises in the distal esophagus. -The progression from Barrett metaplasia to dysplasia and eventually to invasive carcinoma -occurs due to the stepwise accumulation of genetic and epigenetic changes. -The prognosis is poor.
- 25. STOMACH
- 26. Regions of the Stomach The stomach has four regions. 1- The cardiac region, which is near the heart, surrounds the lower esophageal sphincter where food enters the stomach. 2-The fundic region, which holds food temporarily, is an expanded portion superior to the cardiac region. 3-The body region, which comes next, is the main part. 4-The pyloric region narrows to become the pyloric canal leading to the pyloric sphincter through which food enters the duodenum, the first part of the small intestine.
- 28. Acute Inflammation and Stress Ulcers -Acute hemorrhagic gastritis .causes acute inflammation, erosion, and hemorrhage of the gastric mucosa, . secondary to a breakdown of the mucosal barrier and acidinduced injury. .The etiology is diverse, with initiating agents including chronic aspirin or NSAID use, alcohol use, smoking, recent surgery, burns, ischemia, stress, uremia, and chemotherapy. Patients present with epigastric abdominal pain, or with gastric hemorrhage, hematemesis, and melena.
- 30. Gastric stress ulcers --are multiple, small, round, superficial ulcers of the stomach and duodenum. - Predisposing factors include: • NSAID use • Severe stress • Sepsis • Shock • Severe burn or trauma • Elevated intracranial pressure (Cushing ulcers)
- 34. Chronic Gastritis Chronic gastritis is chronic inflammation of the gastric mucosa, eventually leading to atrophy (chronic atrophic gastritis). •
- 35. 1- Fundic type chronic gastritis -an autoimmune atrophic gastritis . It is caused by autoantibodies directed against parietal cells and/or intrinsic factor. - The result is loss of parietal cells, decreased acid secretion, increased serum gastrin (G-cell hyperplasia), and pernicious anemia (megaloblastic anemia due to lack of intrinsic factor and B12 malabsorption). - Women are affected more than men. . Microscopically, mucosal atrophy is seen with loss of glands and parietal cells, chronic lymphoplasmacytic inflammation, and intestinal metaplasia. --.Patients are at increased risk for gastric carcinoma.
- 37. Antral type chronic gastritis (also called Helicobacter pylori gastritis) -is the most common form of chronic gastritis --. The H. pylori organisms are curved, gram-negative rods which produce urease. - The risk of infection increases with age. - Infection is also associated with duodenal/gastric peptic ulcer, and gastric carcinoma with intestinal type histology. Microscopically, H. pylori organisms are visible in the mucous layer of the surface epithelium. Other microscopic features include foci of acute inflammation, chronic inflammation with lymphoid follicles, and intestinal metaplasia.
- 41. Chronic Peptic Ulcer (Benign Ulcer) • Gastric peptic ulcers • are associated with H. pylori (75%). • Most are located in the lesser curvature of the antrum. • Grossly • they are small (<3 cm), sharply demarcated • solitary with round/oval shape, smooth borders, and radiating • mucosal folds. • Duodenal peptic ulcers are more common than gastric peptic ulcers. • Associations include the following: • • H. pylori (~100%) • • Increased gastric acid secretion • • Increased rate of gastric emptying • • Blood group O • • Multiple endocrine neoplasia (MEN) type I • • Zollinger-Ellison syndrome • • Cirrhosis • • Chronic obstructive pulmonary disease • Most duodenal peptic ulcers are located in the anterior wall of the proximal duodenum.
- 44. Gastric Carcinoma (Malignant Ulcer) Risk factors; - Dietary factors , Smoked fish and meats - H. pylori infection - chronic atrophic gastritis, - smoking, - blood type A
- 45. Macroscopical features. -Most gastric carcinomas are located in the lesser curvature of the antrum. -They are large (>3 cm) ulcers with heaped-up margins and a necrotic ulcer base. - They may also occur as a flat or polypoid mass.
- 46. Histological types • The intestinal type shows gland-forming adenocarcinoma microscopically. • The diffuse type shows diffuse infiltration of stomach by poorly differentiated tumor cells, numerous signet-ring cells (whose nuclei are displaced to the periphery by intracellular mucin), and linitis plastica (thickened “leather bottle”–like stomach) gross appearance.
- 52. -Gastric carcinoma may specifically metastasize to the left supraclavicular lymph node (Virchow sentinel node) and to the ovary (Krukenberg tumor). Diagnosis is by endoscopy with biopsy; treatment is gastrectomy. The prognosis is poor, with overall 5-year survival ~30%.
- 53. GASTRIC LYMPHOMA Marginal zone B-cell lymphoma and diffuse large B-cell lymphoma occur in the stomach.