ATI LPN
ATI Quiz Medical Surgical Endocrine Questions
Question 1 of 5
A 46-year-old Hispanic man has had increasing malaise with headaches and easy fatigability for the past 3 months. Physical examination reveals his blood pressure is 200/100 mm Hg. There are no palpable abdominal masses and no costovertebral tenderness. Laboratory studies show hemoglobin, 9.5 g/dL; hematocrit, 28.3%; MCV, 92 μm3; creatinine, 4.5 mg/dL; and urea nitrogen, 42 mg/dL. Urinalysis reveals 3+ hematuria and 3+ proteinuria, but no glucose or leukocytes. A renal biopsy is done; light microscopic examination of the biopsy specimen shows that approximately 50% of the glomeruli appear normal, but the rest show that a portion of the capillary tuft is sclerotic. Immunofluorescence staining shows IgM and C3 deposition in these sclerotic areas. His history is significant for repeated episodes of passing dark brown urine, which failed to respond to corticosteroid therapy. Which of the following mechanisms is most likely responsible for his disease?
Correct Answer: D
Rationale: Corticosteroid-resistant hematuria and proteinuria leading to hypertension and renal failure is typical for focal segmental glomerulosclerosis (FSGS). FSGS is now the most common cause of nephrotic syndrome in adults in the United States. Specialized extracellular areas overlying the glomerular basement membrane between adjacent foot processes of podocytes are called slit diaphragms, and these exert control over glomerular permeability. Mutations in genes affecting several proteins, including nephrin and podocin, have been found in inherited cases of FSGS; podocyte dysfunction, possibly caused by cytokines or unknown toxic factors, may be responsible for acquired cases of FSGS. FSGS with collapsing glomerulopathy is seen in patients with HIV-associated nephropathy. Immune complexes containing microbial antigens cause postinfectious glomerulonephritis (GN). Antiglomerular basement membrane antibodies are responsible for Goodpasture syndrome. C3NeF is an autoantibody directed against C3 convertase, and it is seen in membranoproliferative GN. Inherited defects in basement membrane collagen cause Alport syndrome, also characterized by hematuria, but other congenital abnormalities, such as deafness, are often present, and nephrotic syndrome is uncommon.
Question 2 of 5
A 50-year-old man has had a nonhealing ulcer on the bottom of his foot for 2 months. On examination, the 2-cm ulcer overlies the right first metatarsal head. There is reduced sensation to pinprick in his feet. His visual acuity is reduced bilaterally. Laboratory studies show serum creatinine is 2.9 mg/dL. Which of the following laboratory test findings is he most likely to have?
Correct Answer: A
Rationale: Complications of diabetes mellitus are described in this man: vascular disease, neuropathy, nephropathy, and retinopathy. Hyperglycemia exceeds the capacity of renal tubular reabsorption, so glucose appears in the urine. The other listed findings involve organs that are not typically involved in diabetes mellitus: liver disease with decreased albumin synthesis, hyperaldosteronemia with hypokalemia, decreased marrow function with leukopenia, exocrine pancreatic disease with steatorrhea.
Question 3 of 5
A 37-year-old woman states that, although most of the time she feels fine, she has had episodes of palpitations, tachycardia, tremor, diaphoresis, and headache over the past 3 months. When her symptoms are worse, her blood pressure is measured in the range of 155/90 mm Hg. She collapses suddenly one day and is brought to the hospital, where her ventricular fibrillation is converted successfully to sinus rhythm. On physical examination, there are no remarkable findings. Which of the following laboratory findings is most likely to be reported in this patient?
Correct Answer: D
Rationale: These findings suggest a pheochromocytoma of the adrenal medulla. This is a rare neoplasm, but in cases of episodic hypertension, this diagnosis should be considered. Screening for urinary free catecholamines, metanephrine, and vanillylmandelic acid (VMA) can help to determine the diagnosis.
Question 4 of 5
At the skeletal muscle sarcomere, Ca2+ ions do each of the following, except:
Correct Answer: D
Rationale: Ca2+ binds troponin, exposes actin sites, is stored in SR; ATP hydrolysis is by myosin ATPase, not Ca2+.
Question 5 of 5
What is correct regarding cardiac contractile cells?
Correct Answer: D
Rationale: All are true: unique structure, plateau phase (Ca2+ influx), dual Ca2+ sources.