UWorld Test 5/22/2014 Flashcards
Postoperative urinary retention can be treated with?
Muscarinic agonist like Bethanechol or an alpha1 blocking drug. (anesthesia and analgesia contribute to over distention of bladder, decreased micturition reflex decreased contractiliy of the bladder detrusor muscle and incomplete emptying.
How does inspired partial pressure of O2 change from sealevel to very high altitudes (4300 - 5500 is the highest human habitations) What does PaO2 change to?
Decreases drastically from 150mmHg to 86mmHg. PaO2 drops to around 60mmHg
What happens when you go to high altitutides
High altitutde = hypoxemia => chemoreceptors in aorta and carotid body are activated => increases ventialtory drive => hyperventilation and respiraotyr alkalosis => increase In pH with decrease in PaCO2.To partially compensate for the respiraotyr alkalosis, the kidneys begin to excrete bicarb, causing a mild metabolic acidosis through decreased serum bicarb levels. this begins 48 hours. Long term, renal hypoxia results in increased EPO production with increased RBC and Hb production
What is the triad of symptoms in Ataxia-telangiectasia? What kind of inheritance. Defect?
Ataxia (cerebellar atropy), Angiomas - telangiectasia “superficial blanching nexts of distended capillaries”, deficiency IgA => increased risk of sinopulmonary infections.A/R- defect in ATM gene (normally plays a role in DNA strand repair) which causes DNA strand breaks and arrests cell cycle.
History of gallstones + air in the gallblader and biliary tree on abdominal X-ray - think what?
gallstone ileus
Pathogenesis of ileus? Where does it typically get lodged?
Longstanding cholelithiasis => formation of cholecystenteric fistula between gallbladder and adjoining gut tissue due to persistent pressure on these tissues => fistula allows for passage of stone into small bowel => resulting communication between small bowel and gall bladder leads to air in the gallbladder and biliary tree. Gallstone moves freely through the small bowel and then gets stuck at ileocecal valve (typically only liquids go through here).Obstruction => abdominal pain/distention/vomiting/tenderness to palpation and tinkling bowel sounds
Testicular hydrocele results from serous fluid accumulation in
Tunica vaginalis (embryologically derived from peritoneum. Usually the communication between the processus vaginalis and periotenus is obliterated but when not, a communicating hydrocele can happen.
In overweight individuals, what increases insulin resistance?
Free fatty acids and serum triglycerides. Exact mechanisms unknown. Perhaps serine phosphorylation of insulin receptor’s beta subunit (which is the mechanism of insulin resistance of corticosteroids, tnf-alpha, glucagon). FFA also leads to decreased insulin secretion.
Lung collapse on chest x ray shows up like what?
opacification with trachea deviating towards the collapsed lung
What are the main MOAs of digoxin?
Increases cardiac contractility by inhibiting Na/K pump and increasing intraceullar Ca2+ concentration. Also decreases AV nodal conduction by enhancing parasympathetic tone.
Activating mutations of PRPP can lead to?
Hyperuricemia/gout
Lancet shaped diplococci is what?
Strep pneumo
Strep pneumo identifying characteristics?
Gram positive cocci, alpha hemolytic, optochin sensitive, bile sensitive (i.e. bile soluble)
Severe hypoglycemia (loss of consciousness) is treated with what in a medical/non-medical setting?
Medical setting - iv dextrose 25grams in 50cc non-medical setting - intramuscular indjection of glucagon (increases glucose through glycogenolysis)
What is the most common type of renal cell carcinoma
Clear cell carcinoma - large, rounded or polyglonal cells filled with clear cytoplasm. Triad hematuria, flank pain, and palpable mass in a minority of patients.
