USMLE World Practice Test 1 Question and Answer

ARDS - Damage to the endothelial cells lining the pulmonary capillaries adjacent to the alveoli due to inflammatory cytokines and neutrophils (DAD) --> Proliferation of type II pneumocytes --> Final fibrotic phase Defined as acute lung dysfxn, pulmonary edema, normal left atrial pressure, and a PaO2/FiO2 of <200 Caused by Trauma, pulmonary contusions, infection/sepsis, and fat embolism Analgesic abuse nephropathy - Characterized by marked thickening of the vasa recta capillaries and intermittent tubular necrosis. Eventually, papillary necrosis, focal and segmental glomeruloscelrosis and interstitial infiltration and fibrosis can occur Paget's disease malignancy - Osteosarcoma, arising in the femur, tibia and humerus Osteosarcoma Xray - Destruction of normal trabecular bone pattern, mixed radio dense and radiolucent areas, periosteal new bone formation, lifting of the cortex and Codman's triangle. Adjacent soft tissue usually demonstrates ossification in a "sunburst" pattern "mixed lysis and sclerosis with focal periosteal elevation and reactive new bone formation" Avascular necrosis Xray - Pathognomonic crescent sign indicating subchondral collapse Globus hystericus - Aka globus sensation or "lump in the throat" Emotions commonly as the trigger A/w GERD, upper esophageal sphincter abnormalities, achalasia, psychiatric disorders and stress Retrosternal goiter - One/both of the thyroid lobes grow into the thoracic cavity inlet Pseudobulbar paresis - Caused by conditions such as multiple sclerosis Characterized by dysarthria, dysphagia, dysphonia and impaired movement of the tongue and facial muscles Normal urate crystals have a protective coating of... - ApoE or ApoB Joint infection with bacteria and neutrophils - Acute suppurative arthritis Joint infection with mycobacteria and caveating granulomas - Tuberculous arthritis Joint infection with spirochetes - Lyme disease Pathogenesis of endometriosis - 1. Retrograde menstruation 2. Lymphatic and vascular spread 3. Coelomic metaplasia Leiomyoma histology - Whorled pattern of smooth muscle bundles with intervening connective tissue DNA laddering - The appearance of DNA fragments in multiples of 180 base pairs on gel electrophoresis. A sensitive indicator of apoptosis Due to endonuclease action during karyorrhexis Contact inhibition - The phenomenon whereby cell division halts in G1 in response to contact on all sides by other cells Atropine - Competitive inhibitor of acetylcholine-like agents, acting at the muscarinic receptors of smooth muscle cells Vasomotor rhinitis - Chronic nasal congestion that worsens with abrupt changes in temperature or humidity or with exposure to odors or alcohol. Headaches, anosmia and sinusitis Location of action on the penis of PDE5 inhibitors - Relaxation of the smooth muscle cells that surround the cavernous venous sinuses of the corpora cavernosa