Describe urine in relationship to glomerular filtration, tubular reabsorption and tubular secretion. Urine =:

Correct Answer: D

Rationale: Urine = filtration – reabsorption + secretion e.g., 180 L filtered, 99% reabsorbed, waste added (1.8 L urine). Adding reabsorption increases volume false. Subtracting secretion removes waste wrong. Adding/subtracting reabsorption miscalculates illogical. Correct formula distinguishes it, key to urine composition, unlike additive or subtractive errors.

Correct Answer: D

Rationale: The hypothalamus monitors blood osmolarity osmoreceptors trigger ADH (e.g., water balance). JGA senses pressure not osmolarity directly. Medulla oblongata is respiratory not osmotic. Midbrain is motor unrelated. Hypothalamus's osmotic role distinguishes it, critical for hydration, unlike pressure or neural sites.

Correct Answer: B

Rationale: Cystitis is bladder infection e.g., E. coli common (mucosa). Urethritis is urethra not bladder. Pyelonephritis is kidney higher. Nephritis is inflammation not specific infection. Cystitis's location distinguishes it, critical for bladder pathology, unlike adjacent or vague terms.

Correct Answer: C

Rationale: Juxtaglomerular (JG) cells secrete renin e.g., JGA responds to low BP. Macula densa senses NaCl signals JG, doesn't secrete. Glomerular epithelial (podocytes) filter not secrete. Basement membrane is structural not cellular. JG's renin role distinguishes it, key to RAAS, unlike sensing or structural parts.

Correct Answer: A

Rationale: Renal diabetes (glycosuria) spills glucose into urine at low blood levels e.g., defective PCT transporters (threshold <180 mg/dL). Hemorrhage unrelated blood loss issue. ADH affects water not glucose. Youth prevalence is diabetes mellitus not renal. Low-threshold spill distinguishes it, critical for renal glycosuria, unlike unrelated causes.