Practice Questions Flashcards
In an experiment, surgical incisions are made in a study group of lab rats. Observations about the wounds are recorded over a 2-week period using various chemical mediators. Which of the following steps in the inflammatory-repair response is most likely affected by neutralization of TGF-beta?
A. Chemotaxis of lymphocytes B. Increase in vascular permeability C. Leukocyte extravasation D. Migration of epithelial cells E. Production of collagen
E. Production of collagen
An experiment is conducted involving cellular aspects of wound healing. Components of the extracellular matrix are analyzed to determine their sites of production and their binding patterns to other tissue components. Which of the following molecules synthesized by fibroblasts can best bind to cellular integrins and extracellular collagen and attach epidermal basal cells to basement membrane?
A. Dermatan sulfate B. Fibronectin C. Heparin D. Hyaluronic acid E. Procollagen
B. Fibronectin
An experiment analyzes factors involved in the cell cycle during growth factor-induced cellular regeneration in a tissue culture. Cyclin B synthesis is induced; the cyclin B binds and activates CDK-1. The active kinase produced by this process is most likely to control progression in which of the following phases of the cell cycle?
A. G0 to G1 B. G1 to S C. S to G2 D. G2 to M E. M to G1
D. G2 to M
In an experiment, the role of LDL receptors in uptake of lipids in the liver is studied. A mouse model is created in which the LDL receptor gene is not expressed in the liver. For creating such a knockout mouse, which of the following cells would be most useful?
A. Adult bone marrow mesenchymal progenitor cells B. Embryonic stem cells in culture C. Hematopoietic stem cells D. Hepatic oval cells E. Regenerating hepatocytes
B. Embryonic stem cells in culture
An 11 y/o girl becomes infected with hepatitis A and experiences mild nausea for 1 week. On PE she has minimal RUQ tenderness and scleral icterus. Lab findings include a serum AST of 68, ALT of 75, and total bilirubin of 5.1 mg/dL. Her lab findings most likely result from which of the following changes in her hepatocytes?
A. Cell membrane defects B. Lysosomal autophagy C. Mitochondrial swelling D. Nuclear chromatin clumping E. Ribosomal dispersion
A. Cell membrane defects
A 33 y/o woman has had increasing lethargy and decreased urine output for the past week. Lab studies show her serum creatining is 4.3 mg/dL and urea nitrogen 40 mg/dL. A renal biopsy is performed, and the specimen is examined using electron microscopy. Which of the following morphologic cellular changes most likely suggests a diagnosis of acute tubular necrosis?
A. Chromatin clumping B. Mitochondrial swelling C. Nuclear fragmentation D. Plasma membrane blebs E. Ribosomal disaggregation
C. Nuclear fragmentation
Patients with extensive endothelial injury from E coli sepsis have consumption of coagulation factors as well as an extensive inflammatory response. Administration of activated protein C is most likely to decrease this inflammatory response by reducing the amount of which of the following substances?
A. Complement B. Fibrin C. Kallikrein D. Plasmin E. Thrombin
E. Thrombin
A 68 y/o man has had worsening shortness of breath for the past week. On PE, his temp is 38.3 C. On percussion, there is dullness over the left lung fields. Thoracentesis performed on the left pleural cavity yields 800 mL of cloudy yellow fluid that has a WBC count of 2500/mm with 98% neutrophils and 2% lymphocytes. A gram stain of the fluid shows gram-positive cocci in clusters. Which of the following terms best describes the process occuring in his left pleural cavity?
A. Abscess B. Chronic inflammation C. Edema D. Fibrinous inflammation E. Purulent exudate F. Serous effusion
E. Purulent exudate
A 43 y/o man with a ventricular septal defect has had a cough and fever for the past 2 days. On exam, he has a temp of 37.6 and a cardiac murmur. A blood culture grows streptococcus, viridians group. His ESR is increased. Microbial cels are opsonized and cleared. Which of the following chemical mediators is most important in producing these findings?
A. Bradykinin B. C-reactive protein C. Interferon-y D. Nitric oxide E. Prostaglandin F. Tumor necrosis factor (TNF)
B. C-reactive protein
In an experiment involving observations on wound healing, researchers noted that intracytoplasmic cytoskeletal elements, including actin, interact with the extracellular matrix to promote cell attachment and migration in wound healing. Which of the following substances is most likely responsible for such interaction between the cytoskeleton and the extracellular matrix?
A. Epidermal growth factor B. Fibronectin C. Integrin D. Platelet derived growth factor E. Type IV collagen F. Vascular endothelial growth factor
C. Integrin
A 58 y/o man had chest pain persisting for 4 hours. A radiographic imaging procedure showed an infarction involving a 4-cm area of the posterior left ventricular free wall. Lab findings showed serum creatine kinase of 600 U/L. Which of the following pathological findings would most likely be seen in the left ventricular lesion 1 month later?
A. Chronic inflammation B. Coagulative necrosis C. Complete resolution D. Fibrous scar E. Nodular regeneration
D. Fibrous scar
A 94 y/o woman has dyspnea and an increasing cough with frothy sputum production for the past month. She is afebrile. Which of the following is the most likely mechanism for development of her pulmonary infiltrates?
A. Decreased sodium intake B. Hypoalbuminemia C. Increased hydrostatic pressure D. Inflammation E. Pulmonary venous obstruction
C. Increased hydrostatic pressure
A 15 y/o girl incurs a cut to the sole of her foot after stepping on a piece of broken glass. On exam, a superficial 0.5 cm laceration ceases to bleed within 5 mins after application of local pressure. Which of the following substances is released by endothelium and is most likely to counteract platelet aggregation near this site of injury?
A. Glycoprotein IIb/IIIa B. Platelet-activating factor C. Prostacyclin D. Tissue-type plasminogen activator E. Thrombomodulin F. Thromboxane
C. Prostacyclin
A 58 y/o man has had episodes of prolonged epistaxis in the past 6 months. On exam he has occult blood detected in his stool. Coagulation studies show that his PT is elevated but his PTT, platelet count, and platelet function are all normal. When his plasma is mixed with an equal amount of normal plasma, the PT corrects to normal. Which of the following underlying diseases is most likely to be associated with these findings?
A. Antiphospholipid syndrome B. Factor V Leiden mutation C. Hemophilia A D. Scurvy E. Sepsis with E. Coli F. Vitamin K deficiency
F. Vitamin K deficiency
A 66 y/o woman has the sudden onset of CP that radiates to her neck and left arm. On exam 30 mins later, she is diaphoretic and hypotensive. Her serum troponin I level is elevated. Which of the following drugs is most likely to be administered emergently as thrombolytic therapy for this woman?
A. Aspirin B. Low-molecular-weight heparin C. Nitric oxide D. t-Pa E. Vitamin K
D. t-Pa
