The volume of glomerular filtrate is ______ the volume of urine formed and excreted.

• A. much greater than
• B. equal to
• C. unrelated to
• D. much less than

Answer: (A)

Verified step by step guidance

1. Understand the process of glomerular filtration: Glomerular filtration occurs in the kidneys, where blood plasma is filtered through the glomeruli into the Bowman's capsule. This filtrate contains water, ions, and small molecules but excludes larger molecules like proteins and blood cells.
2. Recognize the role of reabsorption: After filtration, the majority of the glomerular filtrate is reabsorbed back into the bloodstream in the renal tubules. This process ensures that essential substances like water, glucose, and ions are retained while waste products are concentrated into urine.
3. Compare the volumes: The volume of glomerular filtrate produced daily is significantly larger than the volume of urine excreted. For example, humans produce approximately 180 liters of glomerular filtrate per day, but only about 1-2 liters of urine are excreted.
4. Eliminate incorrect options: Based on the physiological process, the volume of glomerular filtrate cannot be equal to, unrelated to, or much less than the volume of urine formed. These options contradict the reabsorption process.
5. Conclude the correct relationship: The correct answer is that the volume of glomerular filtrate is much greater than the volume of urine formed and excreted, due to the extensive reabsorption occurring in the kidneys.