Chapter 25
The Urinary System
Related Clinical Terms
Renal infarct
Area of dead, or necrotic, renal tissue due to blockage
of the vascular supply to the kidney or hemorrhage. A common
cause of localized renal infarct is an obstructed interlobar artery.
Because interlobar arteries do not anastomose, their obstruction
leads to ischemic necrosis of the portions of the kidney they
Analysis of urine to diagnose health or disease. Te most
significant indicators of disease in urine are proteins, glucose,
ketone bodies, blood, and pus.
o-jist) Physician who specializes in diseases
of urinary structures in both sexes and in diseases of the
reproductive tract of males.
Let’s return to Kyle Boulard, whom
we met in the previous chapter. After
two days in the hospital, Mr. Boulard
has recovered from his acute diabetic
crisis and his type 1 diabetes is once again under control. The last
update on his chart before he is discharged includes the following:
BP 150/95, HR 75, temperature 37.2°C
Urine: pH 6.9, negative for glucose and ketones; 24-hour urine
collection reveals 170 mg albumin in urine per day
Mr. Boulard is prescribed a thiazide diuretic and an angiotensin
converting enzyme (ACE) inhibitor. He is counseled on the
importance of keeping his diabetes under control, taking his
medications regularly, and keeping his outpatient follow-up
What is albumin? Is it normally found in the urine? If not, what
does its presence suggest?
Why were these medications prescribed for Mr. Boulard?
Where and how do thiazide diuretics act in the kidneys and
how does this reduce blood pressure?
At his two-week appointment at the outpatient clinic, Mr.
Boulard complains of fatigue, weakness, muscle cramps, and
irregular heartbeats. A physical examination and lab tests produce
the following observations:
BP 133/90, HR 75
Blood K
2.9 mEq/L (normal 3.5–5.5 mEq/L); blood Na
mEq/L (normal 135–145 mEq/L)
Urine K
55 mEq/L (normal
40 mEq/L); urine Na
21 mEq/L
20 mEq/L)
What is Mr. Boulard’s main problem at this point?
Explain how the thiazide diuretic might have caused this
When asked about his medications, Mr. Boulard admits that he did
not fill his ACE inhibitor prescription because it was too expensive. He
could only afford the thiazide medications along with his insulin.
How do ACE inhibitors reduce blood pressure?
Would taking ACE inhibitors and thiazides together have
prevented Mr. Boulard’s current symptoms? Explain.
(Answers in Appendix H)
Case Study
Urinary System
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