A 37-year-old man has blood glucose of 900 mg/dL and Tmax of 380 mg/min. What is the expected amount of glucose in the urine?

Correct Answer: B

Rationale: Glucose in urine = filtration rate - Tmax: 900 mg/dL × 1.25 (GFR 125 mL/min) = 1125 mg/min - 380 = 745 mg/min excess spills (e.g., diabetes). Zero assumes full reabsorption false above Tmax. 380 is Tmax not excreted. 1125 is filtered ignores reabsorption. 745 mg/min distinguishes it, critical for glucosuria calculation, unlike total, max, or nil values.

Correct Answer: B

Rationale: High GFR threatens dehydration/electrolyte depletion tubules can't reabsorb all (e.g., overwhelm Tmax), losing essentials. Waste reabsorption occurs if too low not high. Sluggish flow is low GFR opposite. No effect ignores physiology false. Depletion risk distinguishes it, critical for GFR regulation, unlike waste or flow errors.

Correct Answer: B

Rationale: Inhibiting the pudendal nerve (somatic) contracts the external sphincter delays voiding (e.g., voluntary control). Pelvic nerve inhibition stops reflex misdirected. Hypogastric (sympathetic) inhibition relaxes bladder opposite. Parasympathetic inhibition halts contraction partial. Pudendal's role distinguishes it, critical for continence, unlike visceral or system-wide errors.

Correct Answer: D

Rationale: The distal convoluted tubule has higher secretion e.g., H , K (fine-tuning) vs. proximal's organic focus (e.g., creatinine). Proximal secretes reabsorption dominates. Thin ascending/descending focus on concentration not secretion. Distal's secretion role distinguishes it, key to ion regulation, unlike proximal or loop priorities.

Correct Answer: B

Rationale: Sympathetic constriction of afferent/efferent arterioles lowers GFR less filtration, more Na reaches macula densa (e.g., reduced reabsorption upstream). GFR increase is opposite vasodilation. More Na in PCT reabsorption needs higher flow false. Filtered Na drops low GFR. Macula densa delivery distinguishes it, key to feedback, unlike GFR or reabsorption errors.