Glomerular filtration — MCQs

A pulmonologist reviews spirometry tracings from two patients with dyspnea. Patient A's loop demonstrates a reduced total lung capacity, reduced FVC, normal FEV1/FVC ratio (0.82), and a tall narrow loop. Patient B's loop shows a reduced FEV1/FVC ratio (0.58), increased total lung capacity, and a scooped-out expiratory limb. Which of the following correctly identifies the underlying mechanism responsible for the reduced expiratory flow in Patient B?

A 9-year-old boy is brought to the physician's office by his mother because of facial swelling for the past 2 days. The mother says that her son has always been healthy and active but is becoming increasingly lethargic and now has a puffy face. Upon inquiry, the boy describes a foamy appearance of his urine, but denies having blood in the urine, urinary frequency at night, or pain during urination. He has no history of renal or urinary diseases. Physical examination is unremarkable, except for generalized swelling of the face and pitting edema on the lower limbs. Dipstick analysis reveals 4+ proteinuria. An abdominal ultrasound shows normal kidney size and morphology. A renal biopsy yields no findings under light and fluorescence microscopy; however, glomerular podocyte foot effacement is noted on electron microscopy. Which of the following changes in Starling forces occurs in this patient's condition?

A 70-year-old female with chronic kidney failure secondary to diabetes asks her nephrologist to educate her about the techniques used to evaluate the degree of kidney failure progression. She learns about the concept of glomerular filtration rate (GFR) and learns that it can be estimated by measuring the levels of some substances. The clearance of which of the following substances is the most accurate estimate for GFR?

A 73-year-old male is brought in by ambulance after he was found to be lethargic and confused. He has not been routinely seeing a physician and is unable to recall how he came to be in the hospital. His temperature is 99°F (37°C), blood pressure is 150/95 mmHg, pulse is 75/min, and respirations are 18/min. His past medical history is significant for poorly controlled diabetes and longstanding hypertension, and he says that he has not been taking his medications recently. Labs are obtained and shown below: Serum: Na+: 142 mEq/L Cl-: 105 mEq/L K+: 5 mEq/L HCO3-: 16 mEq/L Urea nitrogen: 51 mg/dL Glucose: 224 mg/dL Creatinine: 2.6 mg/dL Which of the following changes would most likely improve the abnormal parameter that is responsible for this patient's symptoms?

A large pharmaceutical company is seeking healthy volunteers to participate in a drug trial. The drug is excreted in the urine, and the volunteers must agree to laboratory testing before enrolling in the trial. The laboratory results of one volunteer are shown below: Serum glucose (random) 148 mg/dL Sodium 140 mEq/L Potassium 4 mEq/L Chloride 100 mEq/L Serum creatinine 1 mg/dL Urinalysis test results: Glucose absent Sodium 35 mEq/L Potassium 10 mEq/L Chloride 45 mEq/L Creatinine 100 mg/dL Assuming a urine flow rate of 1 mL/min, which set of values below is the clearance of glucose, sodium, and creatinine in this patient?