Question

Human urine as compared to human blood is normally

• A. Hypotonic
• B. Hypertonic
• C. Isotonic
• D. All of the above

Answer 1

The correct option is B Hypertonic

Hypertonic is the solution which contains more solute as compared to the solvent. Humans can survive with limited fluid intake because the kidneys can produce highly concentrated urine more than 4 times as concentrated as blood. The osmolarity of human blood is about 300 milliosmols per liter (mOsm /L). The kidneys can produce urine with an osmolarity of about 1200 mOsm / L. As the initial filtrate passes through various regions of the renal tubule, salt (NaCl) is reabsorbed into the interstitial fluid, and a salt concentration gradient is established. The gradient is used to produce a concentrated urine and makes it more hypertonic. Thus, the correct answer is option B.