Final answer:
The false statement about urine is that it normally contains glucose. Glucose in urine indicates conditions like diabetes mellitus, while normally urine consists of water, urea, and creatinine without proteins or glucose. The correct answer is option 3.
Step-by-step explanation:
Urine is the fluid produced by the kidneys through the filtration of blood, the reabsorption of essential nutrients, and the secretion of waste products. It contains various substances based on the body's metabolic activities and the kidney's filtration process.
Urine typically consists mainly of water, accounting for the largest proportion of its composition, making statement 4 accurate. Additionally, statement 5 is true; under normal conditions, urine doesn't contain significant amounts of proteins. The presence of proteins in urine, known as proteinuria, is often an abnormal finding and can indicate kidney damage or dysfunction.
However, statement 3 is inaccurate. While urine does contain nitrogenous waste products such as urea and creatinine, it does not normally contain glucose. Glucose is not a typical component of urine in healthy individuals. Under normal circumstances, glucose is completely reabsorbed by the kidneys and should not appear in urine. The presence of glucose in urine, known as glucosuria, is a sign of conditions like diabetes or renal disorders where the kidneys are unable to reabsorb all the filtered glucose.
Therefore, statement 3, suggesting that urine normally contains glucose, is false.