A client with Cushing's syndrome is recovering from an elective laparoscopic procedure. Which assessment finding warrants immediate intervention by the nurse?

Correct Answer: A

Rationale: An irregular apical pulse in a client with Cushing's syndrome post-laparoscopy warrants immediate intervention. Cushing's causes hypercortisolism, which can lead to hypokalemia and cardiac arrhythmias, especially under surgical stress. An irregular pulse may indicate a life-threatening dysrhythmia requiring urgent ECG evaluation and electrolyte correction. Purple marks (striae) are typical of Cushing's, a small blood spot is expected post-op, and pitting edema, while concerning, is less acute than a cardiac issue, making the pulse the priority.

Correct Answer: C

Rationale: A Net Filtration Pressure (NFP) of -10 mmHg is negative, indicating that the combined opposing forces (oncotic pressure of 25 mmHg and capsular hydrostatic pressure of 15 mmHg, totaling 40 mmHg) exceed the glomerular hydrostatic pressure (30 mmHg). Normally, NFP is positive (around 10 mmHg) to drive filtration. A negative value means no filtration occurs, as fluid is pushed back into the capillaries rather than filtered, making C the correct interpretation.

Correct Answer: A

Rationale: Juxtaglomerular (JG) cells are modified smooth muscle cells located in the walls of the afferent arterioles (and sometimes efferent) within the juxtaglomerular apparatus. They act as mechanoreceptors, releasing renin in response to low blood pressure, regulating GFR and systemic pressure. Their presence in arteriole walls is a anatomical fact, making A (True) correct.

Correct Answer: B

Rationale: In the distal convoluted tubule (DCT) and collecting duct, 8-15% of filtered water is reabsorbed under the influence of antidiuretic hormone (ADH). ADH increases aquaporin-2 insertion, enhancing water permeability in the collecting duct, with some effect in late DCT. Aldosterone affects Na⁺, and angiotensin II modulates GFR, but ADH drives this water reabsorption, making B correct.

Correct Answer: C

Rationale: The bicarbonate buffer system (HCO₃⁻/H₂CO₃) is the most important in blood, rapidly neutralizing acids or bases via CO₂ exhalation (lungs) and HCO₃⁻ regulation (kidneys). It handles ~70% of extracellular buffering. Proteins (D) and phosphate (B) contribute less, and bone (A) is a long-term reserve, making C the primary system.