ATI LPN
NCLEX Questions on the Renal System Questions
Question 1 of 5
What is the percentage of filtered amount of fluid that enters the glomeruli?
Correct Answer: C
Rationale: About 20% of the plasma entering the glomeruli via the afferent arteriole is filtered into the glomerular capsule, known as the filtration fraction. This is calculated as GFR (125 ml/min) divided by renal plasma flow (625 ml/min), equaling 0.2 or 20%. The remaining 80% exits via the efferent arteriole, making C correct, as 1%, 99%, and 15% do not reflect this physiology.
Question 2 of 5
Most enzymes function optimally at pH?
Correct Answer: B
Rationale: Most human enzymes function optimally at a physiological pH of 7.4, close to blood pH (7.35-7.45), where their active sites maintain proper conformation for catalysis. A pH of 7.8 (A) is slightly alkaline, 6.8 (C) is too acidic for most, and 2 (D) suits gastric enzymes like pepsin, not the majority, making B correct.
Question 3 of 5
The most common, preventable complication of abdominal surgery is:
Correct Answer: A
Rationale: Atelectasis, the collapse of lung alveoli, is the most common preventable complication after abdominal surgery due to shallow breathing from pain or anesthesia effects. It's mitigated by deep breathing exercises and incentive spirometry. Fluid imbalance (B), thrombophlebitis (C), and urinary retention (D) occur but are less frequent and often less preventable with routine nursing interventions, making A the correct answer.
Question 4 of 5
What is the primary function of the kidneys in the urinary system?
Correct Answer: B
Rationale: The kidneys' primary function is blood filtration (B), removing waste (e.g., urea), regulating electrolytes, and maintaining fluid/acid-base balance via glomeruli, producing filtrate for urine. Storage (A) is the bladder's role, contractions (C) aid micturition, and urethra expansion (D) is minor, making B the core function.
Question 5 of 5
Concerning the measurement of renal plasma flow (RPF) and glomerular filtration rate (GFR):
Correct Answer: D
Rationale: Inulin measures GFR (A) as it's filtered without tubular handling, its concentration rises in the proximal tubule (B) due to water reabsorption, and PAH measures RPF (C) as it's filtered and secreted, clearing most from plasma. All are true: inulin's properties suit GFR, its concentration reflects reabsorption, and PAH's clearance reflects RPF, making E (all are correct), reassigned as D, correct.