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Health and medicine

Course: Health and medicine > Unit 1

Lesson 10: Urinary system introduction
Science
Health and medicine
Introduction to human body systems
Urinary system introduction
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Problem

Clinical Application #1: Inulin and Measuring the Glomerular Filtration Rate

Inulin is a compound produced by plants such as artichokes, onions and garlic which does not get secreted nor reabsorbed along the nephron. Because of this special characteristic we can say that the amount of inulin excreted in the urine per minute is equal to the amount that is filtered by the glomerulus per minute (the glomerular filtration rate).
Doctors inject inulin directly into the blood plasma to determine the glomerular filtration rate. Two equations are utilized to determine the glomerular filtration rate. Remember, the inulin excreted per minute and inulin filtered per minute are equivalent to one another since no inulin gets secreted nor absorbed along the nephron.
End of reading passage.
start text, I, n, u, l, i, n, space, e, x, c, r, e, t, e, d, space, p, e, r, space, m, i, n, u, t, e, end text, equals, V, dot, U
  • Where V = rate of urine formation (mL/min)
  • Where U = inulin concentration in urine (mg/mL)
start text, I, n, u, l, i, n, space, f, i, l, t, e, r, e, d, space, p, e, r, space, m, i, n, u, t, e, end text, equals, G, F, R, dot, P
  • Where P = inulin concentration in plasma (mg/mL)
  • Where G, F, R = glomerular filtration rate (mL/min)
Based on the information above, determine the glomerular filtration rate of a patient with an inulin concentration in the urine of 15 mg per mL; an inulin concentration in the plasma of 0.25 mg per mL; and a rate of urine formation of 2 mL per minute.
The patient has a glomerular filtration rate of
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3, slash, 5
  • a simplified improper fraction, like 7, slash, 4
  • a mixed number, like 1, space, 3, slash, 4
  • an exact decimal, like 0, point, 75
  • a multiple of pi, like 12, space, start text, p, i, end text or 2, slash, 3, space, start text, p, i, end text
mL/min
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