General pathology — Past Paper OmpathStudy

General pathology — Questions and Answers Complete review bank: 42 questions recovered from all 25 source pages. General Pathology 1. A 22-year-old man develops marked right lower quadrant abdominal pain over the past day. On physical examination there is rebound tenderness on palpation over the right lower quadrant. Laparoscopic surgery is performed, and the appendix is swollen, erythematous, and partly covered by a yellowish exudate. It is removed, and a microscopic section shows infiltration with numerous neutrophils. The pain experienced by this patient is predominantly the result of which of the following two chemical mediators? A. Complement C3b and IgG B. Interleukin-1 and tumor necrosis factor C. Histamine and serotonin D. Prostaglandin and bradykinin E. Leukotriene and HPETE Answer: D. The findings are those of acute appendicitis. The acute inflammation is marked by neutrophil exudation. Release of a variety of chemical mediators results in the findings associated with inflammation: calor (warmth), rubor (erythema), tumor (swelling), and dolor (pain). The analgesic aspirin, by inhibiting the cyclooxygenase pathway, can decrease prostaglandin synthesis. 2. A 40-year-old woman had laparoscopic surgery 3 months ago. Now she has a small 0.5 cm nodule beneath the skin at the incision site that was sutured. Which of the following cell types is most likely to be most characteristic of the inflammatory response in this situation? A. Mast cell B. Eosinophil C. Giant cell D. Neutrophil E. Plasma cell Answer: C. The suture is a foreign material and produces a foreign body reaction. Persistence of the stimulus recruits macrophages that are activated and transformed to giant cells, in this case foreign body giant cells. 3. A 39-year-old man incurs a burn injury to his hands and arms while working on a propane furnace. Over the next 3 weeks, the burned skin heals without the need for skin grafting. Which of the following is the most critical factor in determining whether the skin in the region of the burn will regenerate? A. Good cardiac output with tissue perfusion B. Persistence of skin appendages C. Maintenance of underlying connective tissue D. Diminished edema and erythema E. Granulation tissue formation Answer: B. The skin appendages have epithelium from which the surface epidermis can regenerate. A partial thickness burn retains epithelial elements in the skin. This is why a full thickness burn is much worse and requires grafting. 4. A 58-year-old woman has had a cough with fever for 3 days. A chest radiograph reveals infiltrates in the right lower lobe. A sputum culture grows Streptococcus pneumoniae. The clearance of these organisms from the lung parenchyma would be most effectively accomplished through generation of which of the following substances by the major inflammatory cell type responding to this infection? A. Platelet activating factor B. Prostaglandin E2 C. Kallikrein D. Leukotriene B4 E. Hydrogen peroxide Answer: E. Hydrogen peroxide is reduced by myeloperoxidase to a powerful oxidant that kills bacteria. She has an acute inflammatory response to a bacterial organism, and the majority of inflammatory cells responding will be neutrophils. 5. A clinical study is performed of patients with pharyngeal infections. The most typical clinical course averages 3 days from the time of onset until the patient sees the physician. Most of these patients experience fever and chills. On physical examination, the most common findings include swelling, erythema, and pharyngeal purulent exudate. Which of the following types of inflammation did these patients most likely have? A. Granulomatous B. Acute C. Gangrenous D. Resolving E. Chronic Answer: B. The short course of days and the purulent exudate are typical features of acute inflammation with a neutrophilic response, most often caused by a bacterial organisms such as group A Streptococcus. Lacking evidence for an acute bacterial infection, avoid use of antibiotics. 6. A 56-year-old man has had increasing dyspnea for 6 years. He has no cough or fever. He had chronic exposure to inhalation of silica dust for many years in his job. A chest x-ray now shows increased interstitial markings and parenchymal 1 to 3 cm solid nodules. His pulmonary problems are most likely to be mediated through which of the following inflammatory processes? A. Neutrophilic infiltrates producing leukotrienes B. Foreign body giant cell formation C. Plasma cell synthesis of immunoglobulins D. Mast cell histamine release E. Macrophage elaboration of cytokines Answer: E. Cytokines including growth factors are released from macrophages that have ingested silica crystals, and these factors stimulate collagen production by fibroblasts, producing interstitial fibrosis and nodule formation that reduces and restricts the amount of normal lung parenchyma and makes breathing more difficult. 7. A 22-year-old woman has premature labor with premature rupture of fetal membranes at 20 weeks gestation.