Drainage of urine from the umbilicus of the neonate is due to:

Correct Answer: B

Rationale: Urine from umbilicus is urachal fistula (patent allantois) not vitelline (gut), ectopia vesicae (exstrophy), or ectopic ureter/urethra. This identifies congenital leak, key for diagnosis, contrasting with other fistulae.

Correct Answer: B

Rationale: The urethra carries urine from bladder to outside final exit (e.g., males ~20 cm, females ~4 cm). Ureters deliver to bladder not outside. Renal pelvis collects not exits. Glomerulus filters not transports. Urethra's external role distinguishes it, key to voiding, unlike internal structures.

Correct Answer: A

Rationale: Formed elements (RBCs, WBCs, platelets) and plasma proteins (e.g., albumin) can't filter too large for glomerular barrier. Glucose filters reabsorbed later. Salts filter freely small ions. Formed elements/glucose mispairs glucose filters. Proteins/salts mix filterable/non-filterable wrong. Size exclusion distinguishes it, key to filtration selectivity, unlike mixed options.

Correct Answer: B

Rationale: Water intake is fluid ingested (drinking), food ingested (e.g., fruits), metabolic processes (e.g., oxidation ~300 mL/day). Air inhaled adds minimal water negligible. Excluding food ignores solids wrong. Excluding metabolism omits internal false. Triple mechanism distinguishes it, key to hydration sources, unlike incomplete sets.

Correct Answer: B

Rationale: ADH decreases urine production inserts aquaporins, reabsorbs water (e.g., concentrated urine). Increased production opposes diuresis. No change ignores ADH false. Dilute misaligns ADH concentrates. Reduced output distinguishes it, critical for osmoregulation, unlike diuresis or neutral effects.