A man's leg was crushed between a car bumper and a wall. His physicians believe their patient has suffered kidney damage from myoglobin blocking glomerular pores. Tests showed the following results:
plasma creatinine: 30 mg/100 mL plasma
24 hour urine specimen: volume = 1 liter
urine creatinine 30 mg/mL urine
A. How many mg of creatinine are in the urine specimen? How much creatinine appears in the urine per hour?
B. What is the patient's creatinine clearance in mL/min?
C. What is the patient's GFR?
D. Is this a normal GFR? Did the patient sustain kidney damage?
A. 1000 mL urine × 30 mg creatinine/mL urine = 30,000 mg creatinine in the specimen.
30,000 mg/24 hr = 1250 mg creatinine.
B. Creatinine clearance = excretion rate of creatinine/plasma concentration creatinine.
clearance = 1250 mg creatinine/hr × 1 hr/60 min/30 mg creatinine/100 mL plasma
= 20.8 mg creatinine/min/0.3 mg creatinine/mL plasma
= 69.4 mL plasma/min
C. GFR approximately equal to clearance rate for creatinine, or approximately 70 mL/min.
D. A more typical value for GFR is 125 mL/min, so 70 mL/min represents a severe decline. Thus, kidney damage
has most likely occurred.
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Answer the following statement true (T) or false (F)
Retrograde transport moves toward or away from the body?
What will be an ideal response?