As the male urethra leaves the urinary bladder, it is surrounded by the:

Correct Answer: C

Rationale: The prostate gland surrounds the male urethra at bladder exit prostatic urethra (e.g., ~20 cm total). Adrenals are kidney-top not urethra. Bulbourethral glands are distal penile urethra. Hilum is kidney not bladder. Prostate's position distinguishes it, key to male anatomy, unlike other glands or sites.

Correct Answer: A

Rationale: PCT (~65% water) and collecting duct (ADH-driven) increase water reabsorption e.g., bulk and regulated recovery. Distal tubule adjusts less water focus. Loop sets gradient not ADH-dependent. PCT/collecting synergy distinguishes it, key to water conservation, unlike partial or gradient-focused pairs.

Correct Answer: C

Rationale: The JGA is between afferent arteriole and distal tubule macula densa/JG cells (e.g., renin release site). Loop is tubular not vascular. Medulla oblongata is brain unrelated. Collecting/PCT lacks JGA wrong. JGA's position distinguishes it, critical for GFR/BP control, unlike tubular or brain errors.

Correct Answer: B

Rationale: Urine is ~95% water rest solutes (e.g., urea, ions ~5%). 100% ignores solutes false. 90% underestimates water too low. 85% overestimates solutes incorrect. 95% distinguishes it, critical for urine composition, unlike absolute or skewed estimates.

Correct Answer: D

Rationale: Skeletal system isn't directly influenced by kidneys bones respond indirectly via vitamin D (e.g., calcium). Cardiovascular is BP/volume direct. Respiratory ties to pH HCO₃⁻ effect. Endocrine involves hormones (renin) direct. Skeletal's indirect link distinguishes it, critical for system specificity, unlike directly impacted systems.