ATI LPN
Urinary System Questions Questions
Question 1 of 5
What is the role of tubular secretion in urine formation?
Correct Answer: B
Rationale: Tubular secretion actively transports substances (e.g., Hâº, Kâº, drugs) from peritubular capillaries into renal tubules (B), aiding waste elimination and pH balance. Reabsorption (A) retrieves substances, filtration (C) is glomerular, and blood pressure control (D) is indirect, making B the correct role.
Question 2 of 5
All of the following occur within one hour of eating a large acid load EXCEPT:
Correct Answer: C
Rationale: Within an hour, buffers (A), lungs (B), and hemoglobin (D) act, but kidneys can't fully eliminate nonvolatile acids or regenerate all bicarbonate (C) that fast—renal response takes hours to days. C is the exception, making it the answer.
Question 3 of 5
In the proximal convoluted tubule, chloride ions are reabsorbed because of:
Correct Answer: C
Rationale: Chloride follows sodium's active reabsorption in the PCT due to electrical attraction (C), maintaining charge balance. It's not actively transported (A), tied to calcium (B), or driven solely by osmosis (D), making C the mechanism.
Question 4 of 5
If MAP increased from 120 mmHg to 210 mmHg, GFR would most likely
Correct Answer: A
Rationale: Mean arterial pressure (MAP) rising from 120 to 210 mmHg increases glomerular hydrostatic pressure, boosting GFR (A), unless autoregulation fails beyond ~160 mmHg. Decrease (B) or no change (C) ignores pressure effects, making A likely.
Question 5 of 5
Urine with a high concentration of C₆Hâ‚â‚‚O₆ is:
Correct Answer: D
Rationale: C₆Hâ‚â‚‚O₆ (glucose) in urine (D) is abnormal (glycosuria) as it's filtered and reabsorbed, not secreted, unless the threshold is exceeded (e.g., diabetes). Normal (A, B) or secreted (C) options misalign, making D correct.